1492    Christopher Columbus's expedition makes landfall in the Caribbean, specifically in The Bahamas. The explorer believes he has reached South Asia

1542    Navigator João Rodrigues Cabrilho of Portugal arrives at what is now San Diego, California, United States.

1606    The ''Susan Constant'', the ''Godspeed'', and the ''Discovery'' depart England carrying settlers who found, at Jamestown, Virginia, the first of the thirteen colonies that became the United States.

1636    A vote of the Great and General Court of the Massachusetts Bay Colony establishes the first college in what would become the United States, today known as Harvard University.

1642    Georgeana, Massachusetts (now known as York, Maine), becomes the first incorporated city in the United States.

1733    The first Masonic Grand Lodge in the future United States is constituted in Massachusetts.

1752    Pennsylvania Hospital, the first hospital in the United States, is opened by Benjamin Franklin.

1759    Battle of the Plains of Abraham: British defeat French near Quebec City in the Seven Years' War, known in the United States as the French and Indian War.

1770    Boston Massacre: Five Americans, including a black man named Crispus Attucks, and a boy, are killed by British troops in an event that would contribute to the outbreak of the American Revolutionary War five years later.

1776    South Carolina becomes the first American colony to declare its independence from Great Britain and set up its own government.

1776    The Battle of Long Island: in what is now Brooklyn, New York, British forces under General William Howe defeat Americans under General George Washington.

1776    World's first submarine attack: the American submersible craft ''Turtle'' attempts to attach a time bomb to the hull of British Admiral Richard Howe's flagship HMS ''Eagle'' in New York Harbor.

1776    The Continental Congress officially names its new union of sovereign states the United States.

1776    American Revolutionary War: Hessian mercenaries capture Fort Washington from the Patriots.

1776    American Revolution: The United Provinces (Low Countries) recognize the independence of the United States.

1776    In the Apollo Room of the Raleigh Tavern in Williamsburg, Virginia, students from the College of William and Mary meet for the first time founding Phi Beta Kappa, the first scholastic fraternity in the United States.

1777    American Revolutionary War: American forces under the command of George Washington repulsed a British attack at the Battle of the Assunpink Creek near Trenton, New Jersey

1777    Vermont becomes the first American territory to abolish slavery.

1777    The U.S. Second Continental Congress passes a resolution that the services of Marquis de Lafayette "be accepted, and that, in consideration of his zeal, illustrious family and connexions, he have the rank and commission of major-general of the United States."

1777    American Revolutionary War: The Americans led by General John Stark rout British and Brunswick troops under Friedrich Baum at the Battle of Bennington in Walloomsac, New York.

1777    Lancaster, Pennsylvania is the capital of the United States, for one day.

1777    The United States celebrates its first Thanksgiving, marking the recent victory by the Americans over General John Burgoyne in the Battle of Saratoga in October.

1778    American Revolutionary War: In Paris the Treaty of Alliance and the Treaty of Amity and Commerce are signed by the United States and France signaling official recognition of the new republic.

1778    The Continental Congress votes to ratify both the Treaty of Amity and Commerce and the Treaty of Alliance with France. The two treaties are the first entered into by the United States government.

1778    The Treaty of Fort Pitt is signed. It is the first formal treaty between the United States and a Native American tribe (the Lenape or Delaware Indians).

1778    The Continental Congress passes the first budget of the United States.

1780    New England's Dark Day: A combination of thick smoke and heavy cloud cover causes complete darkness to fall on Eastern Canada and the New England area of the United States at 10:30 A.M.

1780    American Revolution: British Major John André is arrested as a spy by American soldiers exposing Benedict Arnold's change of sides.

1780    American Revolutionary War: Battle of Kings Mountain American Patriot militia defeat Loyalist irregulars led by British colonel Patrick Ferguson in South Carolina.

1781    American forces backed by a French fleet begin the siege of Yorktown, Virginia, during the American Revolutionary War.

1782    John Adams secures the Dutch Republic's recognition of the United States as an independent government. The house which he had purchased in The Hague, Netherlands becomes the first American embassy.

1782    American privateers attack Lunenburg, Nova Scotia.

1782    American Revolutionary War: Treaty of Paris — In Paris, representatives from the United States and the Kingdom of Great Britain sign preliminary peace articles (later formalized as the 1783 Treaty of Paris).

1783    American Revolutionary War: Spain recognizes United States independence.

1783    First United Empire Loyalists reach Parrtown (later called Saint John), New Brunswick, Canada after leaving the United States.

1783    American Revolutionary War: the war ends with the signing of the Treaty of Paris by the United States and the Kingdom of Great Britain.

1784    Western North Carolina (now eastern Tennessee) declares itself an independent state under the name of Franklin; it wasn’t accepted into the United States, and only lasted for four years.

1785    Frenchman Jean-Pierre Blanchard and American John Jeffries travel from Dover, England, to Calais, France, in a gas balloon.

1786    The oldest musical organization in the United States is founded as the Stoughton Musical Society.

1787    In Philadelphia, Pennsylvania, delegates convene a Constitutional Convention to write a new Constitution for the United States; George Washington presides.

1787    Oliver Ellsworth moves at the Federal Convention to call the government the United States.

1788    Georgia becomes the fourth state to ratify the United States Constitution

1788    Connecticut becomes the fifth state to be admitted to the United States.

1788    American Pioneers to the Northwest Territory arrive at the confluence of the Ohio and Muskingum rivers, establishing Marietta, Ohio as the first permanent American settlement of the new United States in the Northwest Territory, and opening the westward expansion of the new country.

1788    New Hampshire ratifies the Constitution of the United States and is admitted as the 9th state in the United States.

1788    New York ratifies the United States Constitution and becomes the 11th state of the United States.

1789    Georgetown College, the first Roman Catholic college in the United States, is founded in Georgetown, Maryland (now a part of Washington, D.C.)

1789    Pope Pius VI appoints Father John Carroll as the first Catholic bishop in the United States.

1789    A national Thanksgiving Day is observed in the United States as recommended by President George Washington and approved by Congress.

1790    Rhode Island becomes the last of the original United States' colonies to ratify the Constitution and is admitted as the 13th U.S. state.

1790    The United States enacts its first copyright statute, the Copyright Act of 1790.

1791    The Western Confederacy of American Indians wins a major victory over the United States in the Battle of the Wabash.

1792    U.S. President George Washington exercises his authority to veto a bill, the first time this power is used in the United States.

1792    Kentucky is admitted as the 15th state of the United States.

1792    First celebration of Columbus Day in the USA held in New York

1792    In Washington, D.C., the cornerstone of the United States Executive Mansion (known as the White House since 1818) is laid.

1793    The cornerstone of Old East, the oldest state university building in the United States, is laid on the campus of the University of North Carolina

1794    The United States and the Kingdom of Great Britain sign Jay's Treaty, which attempts to resolve some of the lingering problems left over from the American Revolutionary War.

1795    The United States and Spain sign the Treaty of Madrid, which establishes the boundaries between Spanish colonies and the U.S.

1796    The first elephant ever seen in the United States arrives from India.

1796    Tennessee is admitted as the 16th state of the United States.

1796    The United States takes possession of Detroit from Great Britain under terms of the Jay Treaty.

1798    The Mississippi Territory is organized from disputed territory claimed by both the United States and Spain. It is expanded in 1804 and again in 1812.

1798    The Sedition Act becomes law in the United States making it a federal crime to write, publish, or utter false or malicious statements about the United States government.

1800    The United States Library of Congress is established when President John Adams signs legislation to appropriate $5,000 USD to purchase "such books as may be necessary for the use of Congress".

1801    First Barbary War: The American schooner {{USS|Enterprise|1799|6}} captures the Tripolitan polacca ''Tripoli'' in a single-ship action off the coast of modern-day Libya.

1803    Louisiana Purchase: The United States purchases the Louisiana Territory from France for $15 million, more than doubling the size of the young nation.

1803    In New Orleans, Louisiana, Spanish representatives officially transfer the Louisiana Territory to a French representative. Just 20 days later, France transfers the same land to the United States as the Louisiana Purchase.

1804    Louisiana Purchase: In St. Louis, Missouri, a formal ceremony is conducted to transfer ownership of the Louisiana Territory from France to the United States.

1804    Forces sent by Yusuf Karamanli of Tripoli to retake Derne from the Americans attack the city.

1805    First Barbary War: Yusuf Karamanli signs a treaty ending the hostilities between Tripolitania and the United States.

1806    Construction is authorized of the Great National Pike, better known as the Cumberland Road, becoming the first United States federal highway.

1806    Lewis and Clark return to St. Louis after exploring the Pacific Northwest of the United States.

1807    Robert Fulton's first American steamboat leaves New York City for Albany, New York on the Hudson River, inaugurating the first commercial steamboat service in the world.

1808    The importation of slaves into the United States is banned.

1809    Mary Kies becomes the first woman awarded a U.S. patent, for a technique of weaving straw with silk and thread.

1810    United States annexes the former Spanish colony of West Florida.

1811    Tecumseh's War: The Battle of Tippecanoe is fought near present-day Battle Ground, Indiana, United States.

1812    War of 1812: Great Britain revokes the restrictions on American commerce, thus eliminating one of the chief reasons for going to war.

1812    War of 1812: the United States invade Canada at Windsor, Ontario.

1812    War of 1812: American frigate ''USS Constitution'' defeats the British frigate ''HMS Guerriere'' off the coast of Nova Scotia, Canada earning her nickname "Old Ironsides".

1812    War of 1812: In a naval engagement on Lake Erie, American forces capture two British ships: {{HMS|Detroit|1812|6}} and HMS ''Caledonia''.

1813    War of 1812: United States troops capture the capital of Upper Canada, York (present day Toronto, Canada).

1813    War of 1812: In Canada, American forces capture Fort George.

1813    The United States defeats the British Fleet at the Battle of Lake Erie during the War of 1812.

1813    War of 1812: Canadians and Mohawks defeat the Americans in the Battle of Chateauguay.

1814    Americans defeat the British at the Battle of Longwoods between London, Ontario and Thamesville, near present-day Wardsville, Ontario.

1814    War of 1812: In central Alabama, U.S. forces under General Andrew Jackson defeat the Creek at the Battle of Horseshoe Bend.

1814    War of 1812: General Phineas Riall advances toward the Niagara River to halt Jacob Brown's American invaders.

1814    Battle of North Point: an American detachment halts the British land advance to Baltimore in the War of 1812.

1815    New Jersey grants the first American railroad charter to John Stevens.

1817    Opening of the first private mental health hospital in the United States, the Asylum for the Relief of Persons Deprived of the Use of Their Reason (now Friends Hospital) in Philadelphia, Pennsylvania.

1817    At Rome, New York, United States, construction on the Erie Canal begins.

1819    By the Adams-Onís Treaty, Spain sells Florida to the United States for five million U.S. dollars.

1819    The {{SS|Savannah}} leaves port at Savannah, Georgia, United States, on a voyage to become the first steamship to cross the Atlantic Ocean. The ship arrived at Liverpool, England on June 20.

1819    The Bank of Savings in New York City, the first savings bank in the United States, opens.

1819    Norwich University is founded in Vermont as the first private military school in the United States.

1820    Captain Nathaniel Palmer becomes the first American to see Antarctica (the Palmer Peninsula is later named after him).

1821    The United States takes possession of its newly bought territory of Florida from Spain.

1822    The Florida Territory is created in the United States.

1823    Monroe Doctrine: US President James Monroe delivers a speech establishing American neutrality in future European conflicts.

1824    Freed American slaves found Liberia.

1825    The Creek cede the last of their lands in Georgia to the United States government, and migrate west.

1827    The Baltimore & Ohio Railroad is incorporated, becoming the first railroad in America offering commercial transportation of both people and freight.

1828    U.S. President John Quincy Adams signs the Tariff of 1828 into law, protecting wool manufacturers in the United States.

1829    In the United States, William Austin Burt patents the typographer, a precursor to the typewriter.

1830    The first revenue trains in the United States begin service on the Baltimore and Ohio Railroad between Baltimore, Maryland and Ellicott's Mills, Maryland.

1830    The ''Tom Thumb'' presages the first railway service in the United States.

1831    In Southampton County, Virginia, escaped slave Nat Turner is captured and arrested for leading the bloodiest slave rebellion in United States history.

1832    Indian Wars: The Black Hawk War begins – the Sauk warrior Black Hawk begins a war with the United States.

1832    Black Hawk War: Around three-hundred United States 6th Infantry troops leave St. Louis, Missouri to fight the Sauk Native Americans.

1835    P. T. Barnum and his circus start their first tour of the United States.

1835    The Treaty of New Echota is signed, ceding all the lands of the Cherokee east of the Mississippi River to the United States.

1836    Samuel Colt is granted an United States patent for the Colt revolver.

1837    Battle of Lake Okeechobee: United States forces defeat Seminole Native Americans.

1838    Tennessee enacts the first prohibition law in the United States

1840    Captain Charles Wilkes circumnavigates Antarctica, claiming what became known as Wilkes Land for the United States.

1840    The Great Natchez Tornado strikes Natchez, Mississippi killing 317 people. It is the second deadliest tornado in United States history.

1842    John Greenough is granted the first U.S. patent for the sewing machine.

1842    The Webster-Ashburton Treaty is signed, establishing the United States-Canada border east of the Rocky Mountains.

1843    The first minstrel show in the United States, The Virginia Minstrels, opens (Bowery Amphitheatre in New York City).

1843    The Cathedral of Our Lady of Peace in Honolulu, Hawaii is dedicated. Now the cathedral of the Roman Catholic Diocese of Honolulu, it is the oldest Roman Catholic cathedral in continuous use in the United States.

1845    President John Tyler signs a bill authorizing the United States to annex the Republic of Texas.

1845    Manifest Destiny: US President James K. Polk announces to Congress that the United States should aggressively expand into the West.

1846    In Austin, Texas the newly formed Texas state government is officially installed. The Republic of Texas government officially transfers power to the State of Texas government following Texas' annexation by the United States.

1846    Mexican-American War: The United States declares war on Mexico.

1846    Mexican-American War: President Mariano Paredes of Mexico unofficially declares war on the United States.

1846    Bear Flag Revolt begins – Anglo settlers in Sonoma, California, start a rebellion against Mexico and proclaim the California Republic.

1846    The Oregon Treaty establishes the 49th parallel as the border between the United States and Canada, from the Rocky Mountains to the Strait of Juan de Fuca.

1846    Mexican-American War: American troops occupy Monterey and Yerba Buena, thus beginning the U.S. conquest of California.

1846    U.S. forces led by Zachary Taylor capture the Mexican city of Monterrey.

1847    Samuel Colt sells his first revolver pistol to the United States government.

1847    Cumberland School of Law is founded in Lebanon, Tennessee, United States, one of only 15 law schools to exist in the United States at the end of 1847.

1847    Cumberland School of Law is founded in Lebanon, Tennessee, United States, one of only 15 law schools to exist in the United States at the end of 1847.

1847    Mexican-American War: Six teenage military cadets known as Niños Héroes die defending Chapultepec Castle in the Battle of Chapultepec. American General Winfield Scott captures Mexico City in the Mexican-American War.

1848    The United States annexes New Mexico.

1849    Regular steamboat service from the west to the east coast of the United States begins with the arrival of the SS ''California'' in San Francisco Bay, 4 months 22 days after leaving New York Harbor.

1853    Gadsden Purchase: The United States buys land from Mexico to facilitate railroad building in the Southwest.

1854    Commodore Matthew Perry signs the Treaty of Kanagawa with the Japanese government, opening the ports of Shimoda and Hakodate to American trade.

1855    Texas is linked by telegraph to the rest of the United States, with the completion of a connection between New Orleans and Marshall, Texas.

1855    American adventurer William Walker departs from San Francisco with about 60 men to conquer Nicaragua.

1855    American adventurer William Walker conquers Nicaragua.

1855    Indian Wars: in Nebraska, 700 soldiers under United States General William S. Harney avenge the Grattan Massacre by attacking a Sioux village and killing 100 between men, women and children.

1858    United States and Japan sign the Harris Treaty.

1859    Daniel E. Sickles, NY congressman, is acquitted of murder on grounds of temporary insanity. This is the 1st time this defense is successfully used in the United States.

1859    Pig War: Ambiguity in the Oregon Treaty leads to the "Northwestern Boundary Dispute" between U.S. and British/Canadian settlers.

1859    Joshua A. Norton declares himself "Emperor Norton I" of the United States.

1860    The first successful United States Pony Express run from Saint Joseph, Missouri to Sacramento, California begins.

1860    The Prince of Wales (later King Edward VII of the United Kingdom) visits the United States.

1860    South Carolina becomes the first state to secede from the United States.

1861    Alabama secedes from the United States.

1861    American Civil War: Georgia joins South Carolina, Florida, Mississippi, and Alabama in seceding from the United States.

1861    American Civil War: Texas secedes from the United States.

1861    American Civil War: Virginia secedes from the United States.

1861    American Civil War: Confederate General Leonidas Polk invades neutral Kentucky, prompting the state legislature to ask for Union assistance.

1861    The First Transcontinental Telegraph line across the United States is completed, spelling the end for the 18-month-old Pony Express.

1861    American Civil War: Citing failing health, Union General Winfield Scott resigns as Commander of the United States Army.

1861    American Civil War: Western Department Union General John C. Fremont is relieved of command and replaced by David Hunter.

1861    American Civil War: Battle of Belmont: In Belmont, Missouri, Union forces led by General Ulysses S. Grant overrun a Confederate camp but are forced to retreat when Confederate reinforcements arrive.

1861    American Civil War: The ''Trent Affair'': Confederate diplomatic envoys James M. Mason and John Slidell are freed by the United States government, thus heading off a possible war between the United States and Britain.

1862    The first American ironclad warship, the {{USS|Monitor}} is launched.

1862    American Civil War: Ulysses S. Grant gives the United States its first victory of the war, by capturing Fort Henry, Tennessee, known as the Battle of Fort Henry.

1862    American Civil War: The U.S. federal government forbids all Union army officers to return fugitive slaves, thus effectively annulling the Fugitive Slave Law of 1850 and setting the stage for the Emancipation Proclamation.

1862    U.S. federal troops occupy Baton Rouge, Louisiana.

1862    The United States and Britain agree to suppress the slave trade.

1862    American Civil War: President Abraham Lincoln reluctantly restores Union General George B. McClellan to full command after General John Pope's disastrous defeat at the Second Battle of Bull Run.

1862    American Civil War: Union General Ambrose Burnside assumes command of the Army of the Potomac, after George B. McClellan is removed.

1862    American Civil War: In the Battle of Cane Hill, Union troops under General John Blunt defeat General John Marmaduke's Confederates.

1862    American Civil War: Abraham Lincoln signs an act that admits West Virginia to the Union, thus dividing Virginia in two.

1863    United States begins its first military draft; exemptions cost $300.

1863    American Civil War: In Charleston, South Carolina, Union batteries and ships bombard Confederate-held Fort Sumter.

1863    American Civil War: Battle of Campbell's Station near Knoxville, Tennessee. Confederate troops unsuccessfully attack Union forces.

1863    American Civil War: Battle of Chattanooga begins – Union forces led by General Ulysses S. Grant reinforce troops at Chattanooga, Tennessee and counter-attack Confederate troops.

1864    American Civil War: Kilpatrick-Dahlgren Raid fails – plans to free 15,000 Union soldiers being held near Richmond, Virginia are thwarted.

1864    During the American Civil War, Union forces led by General William T. Sherman launch an assault on Atlanta, Georgia.

1864    American Civil War: Union General William Tecumseh Sherman burns Atlanta, Georgia and starts Sherman's March to the Sea. thumb

1864    American Civil War: Sherman's March to the Sea: Confederate General John Bell Hood invades Tennessee in an unsuccessful attempt to draw Union General William T. Sherman from Georgia.

1864    American Civil War: Battle of Franklin — The Army of Tennessee led by General John Bell Hood mounts a dramatically unsuccessful frontal assault on Union positions commanded by John McAllister Schofield around Franklin, Tennessee, with Hood lost six generals and almost a third of his troops.

1865    In the United States, Delaware voters reject the Thirteenth Amendment to the U.S. Constitution, and vote to continue the practice of slavery. (Delaware finally ratifies the amendment on February 12, 1901.)

1865    American Civil War: Columbia, South Carolina, is burned as Confederate forces flee from advancing Union forces.

1865    American Civil War: The Siege of Petersburg is broken – Union troops capture the trenches around Petersburg, Virginia, forcing Confederate General Robert E. Lee to retreat.

1865    American Civil War: A day after Union forces capture Richmond, Virginia, U.S. President Abraham Lincoln visits the Confederate capital.

1866    Memorial Day first celebrated in United States at Waterloo, New York.

1866    The Fenians are driven out of Fort Erie, Ontario, into the United States.

1867    The United States takes possession of the, at this point unoccupied, Midway Atoll.

1867    The United States takes control of Midway Island.

1867    United States takes possession of Alaska after purchasing it from Russia for $7.2 million. Celebrated annually in the state as Alaska Day.

1867    At Tremont Temple in Boston, British author Charles Dickens gives his first public reading in the United States.

1867    United States claims Midway Atoll, the first territory annexed outside Continental limits.

1868    Decoration Day (the predecessor of the modern "Memorial Day") is observed in the United States for the first time (By "Commander-in-chief of the Grand Army of the Republic" John A. Logan's proclamation on May 5).

1868    The 14th Amendment to the United States Constitution is ratified guaranteeing African Americans full citizenship and all persons in the United States due process of law.

1870    The Christian holiday of Christmas is declared a federal holiday in the United States.

1870    Louisa Ann Swain of Laramie, Wyoming becomes the first woman in the United States to cast a vote legally after 1807.

1870    In the United States, the Weather Bureau (later renamed the National Weather Service) makes its first official meteorological forecast.

1872    The crewless American ship ''Mary Celeste'' is found by the British brig ''Dei Gratia'' (the ship had been abandoned for nine days but was only slightly damaged).

1873    Levi Strauss and Jacob Davis receive a U.S. patent for blue jeans with copper rivets.

1874    Hawaii signs a treaty with the United States granting exclusive trading rights.

1876    The United States orders all Native Americans to move into reservations.

1876    Indian Wars: In retaliation for the American defeat at the Battle of the Little Bighorn, United States Army troops sack Chief Dull Knife's sleeping Cheyenne village at the headwaters of the Powder River.

1877    Chief Crazy Horse of the Oglala Sioux surrenders to United States troops in Nebraska.

1878    ''Yale Daily News'' becomes the first daily college newspaper in the United States.

1879    Women's rights: American President Rutherford B. Hayes signs a bill allowing female attorneys to argue cases before the Supreme Court of the United States.

1881    The world's first international telephone call is made between St. Stephen, New Brunswick, Canada, and Calais, Maine, United States.

1881    Indian Wars: Sioux Chief Sitting Bull leads the last of his fugitive people in surrender to United States troops at Fort Buford, North Dakota

1882    The world's first commercial hydroelectric power plant (later known as Appleton Edison Light Company) begins operation on the Fox River in Appleton, Wisconsin, United States.

1883    The Pendleton Civil Service Reform Act, establishing the United States Civil Service, is passed.

1884    Proclamation of the demand for eight-hour workday in the United States.

1886    Haymarket Square Riot: A bomb is thrown at policemen trying to break up a labor rally in Chicago, Illinois, United States, killing eight and wounding 60. The police fire into the crowd.

1886    The people of France offer the Statue of Liberty to the people of the United States.

1887    Argonia, Kansas elects Susanna M. Salter as the first female mayor in the United States.

1887    The United States receives rights to Pearl Harbor, Hawaii.

1888    The first successful adding machine in the United States is patented by William Seward Burroughs.

1889    Hyde Park and several other Illinois townships vote to be annexed by Chicago, forming the largest United States city in area and second largest in population.

1890    United States soldiers kill more than 200 Oglala Lakota people with four Hotchkiss guns in the Wounded Knee Massacre.

1892    Ellis Island opens to begin processing immigrants into the United States.

1892    Charles Duryea claims to have driven the first automobile in the United States, in Springfield, Massachusetts.

1892    The New Orleans general strike begins, uniting black and white American trade unionists in a successful four-day general strike action for the first time.

1893    The first American-made automobile, built by the Duryea Brothers, is displayed.

1894    Coxey's Army, the first significant American protest march, departs Massillon, Ohio for Washington D.C.

1895    The first gasoline-powered race in the United States. First prize: $2,000

1897    A treaty annexing the Republic of Hawaii to the United States is signed; the Republic would not be dissolved until a year later.

1897    Lattimer massacre: A sheriff's posse kills 20 unarmed immigrant miners in Pennsylvania, United States.

1898    Spanish-American War: The {{USS|Maine|ACR-1|6}} explodes and sinks in Havana harbor in Cuba, killing more than 260. This event leads the United States to declare war on Spain.

1898    Spanish-American War: The U.S. Congress, on April 25, recognizes that a state of war exists between the United States and Spain as of this date.

1898    Spanish-American War: The United States declares war on Spain.

1898    Spanish-American War: U.S. war ships set sail for Cuba.

1898    The United States captures Guam from Spain.

1898    U.S. President William McKinley signs the Newlands Resolution annexing Hawaii as a territory of the United States.

1898    The Hawaiian flag is lowered from Iolani Palace in an elaborate annexation ceremony and replaced with the flag of the United States to signify the transfer of sovereignty from the Republic of Hawai`i to the United States.

1898    United States takes possession of Puerto Rico.

1899    Spanish-American War: The Treaty of Paris, a peace treaty between the United States and Spain, is ratified by the United States Senate.

1899    Spain cedes Puerto Rico to the United States.

1899    Henry Bliss is the first person in the United States to be killed in an automobile accident.

1900    The United States and the United Kingdom sign a treaty for the Panama Canal

1900    A joint European-Japanese-United States force (Eight-Nation Alliance) occupies Beijing, in a campaign to end the bloody Boxer Rebellion in China.

1900    Filipino resistance fighters defeat a small American column in the Battle of Pulang Lupa, during the Philippine-American War.

1900    Philippine-American War: Filipinos under Juan Cailles defeat Americans under Colonel Benjamin F. Cheatham at Mabitac.

1901    Silliman University is founded in the Philippines. The first American private school in the country.

1902    "Electric Theatre", the first full-time movie theater in the United States, opens in Los Angeles, California.

1902    The United States buys the rights to the Panama Canal from France.

1902    In the United States, a five month strike by United Mine Workers ends.

1903    El Yunque National Forest in Puerto Rico becomes part of the United States National Forest System as the Luquillo Forest Reserve.

1903    Cuba leases Guantánamo Bay to the United States "in perpetuity".

1903    The Hay-Herran Treaty, granting the United States the right to build the Panama Canal, is ratified by the United States Senate. The Colombian Senate would later reject the treaty.

1903    With the encouragement of the United States, Panama separates from Colombia.

1903    The Hay-Bunau-Varilla Treaty is signed by the United States and Panama, giving the United States exclusive rights over the Panama Canal Zone.

1904    Construction begins by the United States on the Panama Canal.

1904    Polytechnic University of the Philippines founded as Manila Business School through the superintendence of the American C.A. O'Reilley.

1904    The first underground New York City Subway line opens; the system becomes the biggest in United States, and one of the biggest in world.

1906    San Francisco public school board sparks United States diplomatic crisis with Japan by ordering Japanese students to be taught in racially segregated schools.

1907    The cornerstone is laid at Washington National Cathedral in the U.S. capital.

1909    United States troops leave Cuba with the exception of Guantanamo Bay Naval Base after being there since the Spanish-American War.

1910    African-American boxer Jack Johnson knocks out white boxer Jim Jeffries in a heavyweight boxing match sparking race riots across the United States.

1910    The first US patent for inventing the traffic lights system is issued to Ernest E. Sirrine.

1911    Victor Berger (Wisconsin) becomes the first socialist congressman in U.S..

1912    The Girl Guides (later renamed the Girl Scouts of the USA) are founded in the United States.

1912    Massachusetts becomes the first state of the United States to set a minimum wage.

1912    United States Marines invade Nicaragua to support the U.S.-backed government installed there after José Santos Zelaya had resigned three years earlier.

1912    United States Marines invade Nicaragua to support the U.S.-backed government installed there after José Santos Zelaya had resigned three years earlier.

1912    Alaska becomes a United States territory.

1913    Dedication of the Lincoln Highway, the first automobile road across United States.

1913    The United States introduces an income tax.

1914    World War I: Germany invades Belgium. In response, the United Kingdom declares war on Germany. The United States declare their neutrality.

1914    A male servant of American architect Frank Lloyd Wright sets fire to the living quarters of the architect's Wisconsin home, Taliesin, murders seven people and burns the living quarters to the ground.

1914    The United States Federal Trade Commission (FTC) is established by the Federal Trade Commission Act.

1914    The Federal Reserve Bank of the United States officially opens.

1915    Jewish American Leo Frank is lynched for the alleged murder of a 13-year-old girl in Marietta, Georgia.

1916    Eight American planes take off in pursuit of Pancho Villa, the first United States air-combat mission in history.

1916    The United States passes the Philippine Autonomy Act.

1916    Jeannette Rankin is the first woman elected to the United States Congress.

1917    World War I: The United States breaks off diplomatic relations with Germany a day after the latter announced a new policy of unrestricted submarine warfare.

1917    World War I: The U.S. ambassador to the United Kingdom is given the Zimmermann Telegram, in which Germany pledges to ensure the return of New Mexico, Texas, and Arizona to Mexico if Mexico declares war on the United States.

1917    World War I: The U.S. ambassador to the United Kingdom is given the Zimmermann Telegram, in which Germany pledges to ensure the return of New Mexico, Texas, and Arizona to Mexico if Mexico declares war on the United States.

1917    World War I: Conscription begins in the United States as "Army registration day".

1917    World War I: The United States declares war on Austria-Hungary.

1918    Great train wreck of 1918: in Nashville, Tennessee, an inbound local train collides with an outbound express killing 101 and injuring 171 people, making it the deadliest rail accident in United States history.

1918    World War I: In the Argonne Forest in France, United States Corporal Alvin C. York leads an attack that kills 25 German soldiers and captures 132.

1918    U.S. President Woodrow Wilson sails for the World War I peace talks in Versailles, becoming the first US president to travel to Europe while in office.

1919    Temperance movement: The United States ratifies the Eighteenth Amendment to the United States Constitution, authorizing Prohibition in the United States one year after ratification.

1919    Oregon places a 1 cent per U.S. gallon tax on gasoline, becoming the first U.S. state to levy a gasoline tax.

1919    Leslie Irvin of the United States makes the first successful voluntary free-fall parachute jump using a new kind of self-contained parachute.

1919    The steel strike of 1919, led by the Amalgamated Association of Iron and Steel Workers, begins in Pennsylvania before spreading across the United States.

1920    The National Football League, (NFL), is founded in the United States.

1920    The National Football League is organized in Canton, Ohio, United States.

1920    In the United States, KDKA of Pittsburgh, Pennsylvania starts broadcasting as the first commercial radio station. The first broadcast is the result of the U.S. presidential election, 1920.

1921    Tulsa Race Riot: A civil unrest in Tulsa, Oklahoma, United States, the official death toll is 39, but recent investigations suggest the actual toll may be much higher.

1922    The Washington Naval Treaty is signed in Washington, D.C., limiting the naval armaments of United States, Britain, Japan, France, and Italy.

1922    In Washington D. C., Charles Evans Hughes signs the Hughes-Peynado agreement, that ends the occupation of Dominican Republic by the United States.

1924    Capital punishment: The first state execution in the United States by gas chamber takes place in Nevada.

1924    American occupying forces leave the Dominican Republic.

1924    Nellie Tayloe Ross of Wyoming is elected the first female governor in the United States.

1925    The American astronomer Edwin Hubble announces the discovery of galaxies outside the Milky Way.

1925    Nellie Tayloe Ross of Wyoming becomes the first female governor in the United States.

1925    The U.S. Zeppelin {{USS|Shenandoah|ZR-1|6}} crashes, killing 14.

1928    The Okeechobee Hurricane strikes southeastern Florida, killing upwards of 2,500 people. It is the third deadliest natural disaster in United States history, behind the Galveston Hurricane of 1900 and the 1906 San Francisco earthquake.

1928    The Republic of China is recognised by the United States.

1928    The airship, the Graf Zeppelin completes its first trans-Atlantic flight, landing at Lakehurst, New Jersey, United States.

1930    The United Kingdom, Japan and the United States sign the London Naval Treaty regulating submarine warfare and limiting shipbuilding.

1930    W1XAV in Boston, Massachusetts broadcasts video from the CBS radio orchestra program, ''The Fox Trappers''. The broadcast also includes the first television commercial in the United States, an advertisement for I.J. Fox Furriers, who sponsored the radio show.

1931    The United States officially adopts ''The Star-Spangled Banner'' as its national anthem.

1932    ''TIME'' magazine features eccentric American politician William "Alfalfa" Murray on its cover after Murray stated his intention to run for President of the United States.

1932    Amelia Earhart becomes the first woman to fly across the United States non-stop (from Los Angeles to Newark, New Jersey).

1933    Minnie D. Craig becomes the first female elected as Speaker of the North Dakota House of Representatives, the first female to hold a Speaker position anywhere in the United States.

1933    United States recognizes Soviet Union.

1934    Alcatraz Island becomes a United States federal prison.

1934    Oskaloosa, Iowa, becomes the first municipality in the United States to fingerprint all of its citizens.

1935    "Black Sunday Storm", the worst dust storm of the U.S. Dust Bowl.

1935    Dr. Robert Smith takes his last drink, and Alcoholics Anonymous is founded in Akron, Ohio, United States, by him and Bill Wilson.

1935    The National Labor Relations Act, which governs labor relations in the United States, is signed into law by President Franklin D. Roosevelt.

1935    United States Social Security Act passes, creating a government pension system for the retired.

1937    Wallace H. Carothers receives a United States patent for nylon.

1937    Pennsylvania becomes the first (and only) state of the United States to celebrate Flag Day officially as a state holiday.

1937    Theodore Cole and Ralph Roe attempt to escape from the American federal prison on Alcatraz Island in San Francisco Bay; neither is ever seen again.

1938    The Civil Aeronautics Act is signed into law, forming the Civil Aeronautics Authority in the United States.

1938    The Thousand Islands Bridge, connecting New York State, United States with Ontario, Canada over the St. Lawrence River, is dedicated by U.S. President Franklin D. Roosevelt.

1938    Orson Welles broadcasts his radio play of H. G. Wells's ''The War of the Worlds'', causing anxiety in some of the audience in the United States.

1940    Booker T. Washington becomes the first African American to be depicted on a United States postage stamp.

1940    The United States' Under Secretary of State Sumner Welles issues a declaration on the U.S. non-recognition policy of the Soviet annexation and incorporation of three Baltic States: Estonia, Latvia and Lithuania.

1940    World War II: the McCollum memo proposes bringing the United States into the war in Europe by provoking the Japanese to attack the United States.

1941    The United Service Organization (USO) is created to entertain American troops.

1941    W47NV (now known as WSM-FM) begins operations in Nashville, Tennessee becoming the first FM radio station in the U.S..

1941    The Grand Coulee Dam in Washington, United States, begins to generate electricity.

1941    World War II: U.S. forces land in Iceland, taking over from an earlier British occupation.

1941    World War II: in response to the Japanese occupation of French Indo-China, US President Franklin D. Roosevelt orders the seizure of all Japanese assets in the United States.

1941    World War II: a German submarine makes the first attack against a United States ship, the {{USS|Greer|DD-145|6}}.

1941    World War II: The United States grants Lend-Lease to the Free French.

1941    World War II: Germany and Italy declare war on the United States, following the Americans' declaration of war on Japan in the wake of the attack on Pearl Harbor. The United States, in turn, declares war on Germany and Italy.

1941    World War II: UK declares war on Bulgaria. Hungary and Romania declare war on the United States. India declares war on Japan.

1941    World War II: Hungary and Romania declare war on the United States.

1941    U.S. President Franklin D. Roosevelt signs a bill establishing the fourth Thursday in November as Thanksgiving Day in the United States.

1942    World War II: The Allies bombard Bangkok, leading Thailand to the decision of war declaration against the United States and United Kingdom .

1942    World War II: Thailand declares war on the United States and United Kingdom.

1942    World War II: The first United States forces arrive in Europe landing in Northern Ireland.

1942    World War II: Top United States military leaders hold their first formal meeting to discuss American military strategy in the war.

1942    World War II: Top United States military leaders hold their first formal meeting to discuss American military strategy in the war.

1942    Year-round Daylight saving time is re-instated in the United States as a wartime measure to help conserve energy resources.

1942    World War II: Japanese forces begin an assault on the United States and Filipino troops on the Bataan Peninsula.

1942    World War II: Japanese naval troops invade Tulagi Island in the Solomon Islands during the first part of Operation Mo that results in the Battle of the Coral Sea between Japanese forces and forces from the United States and Australia.

1942    World War II: The Battle of the Coral Sea begins with an attack by aircraft from the United States aircraft carrier ''Yorktown'' on Japanese naval forces at Tulagi Island in the Solomon Islands. The Japanese forces had invaded Tulagi the day before.

1942    World War II: United States declares war on Bulgaria, Hungary, and Romania.

1942    The United States opens its Office of War Information.

1942    The United States establish the Office of Strategic Services.

1942    World War II: the Battle of Guadalcanal begins – United States Marines initiate the first American offensive of the war with landings on Guadalcanal and Tulagi in the Solomon Islands.

1942    World War II: The Battle of the Eastern Solomons. Japanese aircraft carrier ''Ryūjō'' is sunk and US carrier {{USS|Enterprise|CV-6|6}} heavily damaged.

1942    World War II: The Naval Battle of Guadalcanal between Japanese and American forces begins near Guadalcanal. The battle lasts for three days.

1943    World War II: The United States and United Kingdom give up territorial rights in China.

1943    World War II: United States General Dwight D. Eisenhower publicly announces the Allied armistice with Italy.

1943    World War II: U.S. General Dwight D. Eisenhower and Italian Marshal Pietro Badoglio sign an armistice aboard the Royal Navy battleship {{HMS|Nelson|28|6}} off Malta.

1943    World War II: American bombers strike a hydro-electric power facility and heavy water factory in German-controlled Vemork, Norway.

1944    World War II: United States troops land on Majuro.

1944    World War II: American forces land on Kwajalein Atoll and other islands in the Japanese-held Marshall Islands.

1944    World War II: During Anzio campaign 1st Ranger Battalion (Darby's Rangers) is destroyed behind enemy lines in a heavily outnumbered encounter at Battle of Cisterna, Italy.

1944    World War II: The United States takes Eniwetok Island.

1944    Navigation errors lead to an accidental American bombing of the Swiss city of Schaffhausen.

1944    World War II: Battle of Saipan: The United States invade Saipan.

1944    World War II: The Battle of Cherbourg ends with the fall of the strategically valuable port to American forces.

1944    United States forces land in the Philippines.

1945    US Army private Eddie Slovik is executed for desertion, the first such execution of an American soldier since the Civil War.

1945    President Franklin D. Roosevelt meets with King Ibn Saud of Saudi Arabia aboard the USS ''Quincy'', officially starting the U.S.-Saudi diplomatic relationship.

1945    World War II: American troops seize the Ludendorff Bridge over the Rhine River at Remagen.

1945    World War II: US troops capture Leipzig, Germany, only to later cede the city to the Soviet Union.

1945    Elbe Day: United States and Soviet troops meet in Torgau along the River Elbe, cutting the ''Wehrmacht'' of Nazi Germany in two, a milestone in the approaching end of World War II in Europe.

1945    The Dachau concentration camp is liberated by United States troops.

1945    Manhattan Project: the Atomic Age begins when the United States successfully detonates a plutonium-based test nuclear weapon at the Trinity site near Alamogordo, New Mexico.

1945    World War II: Hiroshima is devastated when the atomic bomb "Little Boy" is dropped by the United States B-29 ''Enola Gay''. Around 70,000 people are killed instantly, and some tens of thousands die in subsequent years from burns and radiation poisoning.

1945    The United Nations Charter is signed by the United States, which becomes the third nation to join.

1945    World War II: Nagasaki is devastated when an atomic bomb, ''Fat Man'', is dropped by the United States B-29 ''Bockscar''. 39,000 people are killed outright.

1945    The USSR's nuclear program receives plans for the United States plutonium bomb from Klaus Fuchs at the Los Alamos National Laboratory.

1945    Cold War: Operation Paperclip: The United States Army secretly admits 88 German scientists and engineers to help in the development of rocket technology.

1945    By a vote of 65 to 7, the United States Senate approves United States participation in the United Nations (the UN was established on October 24, 1945).

1946    After 381 years of near-continuous colonial rule by various powers, the Philippines attains full independence from the United States.

1946    Mother Frances Xavier Cabrini becomes the first American to be canonized.

1947    The American and British occupation zones in Germany, after the World War II, merge to form the Bizone, that later became the Federal Republic of Germany.

1947    Bernard Baruch coins the term "Cold War" to describe the relationship between the United States and the Soviet Union.

1948    With a Musicians Union ban lifted, the first telecasts of classical music in the United States, under Eugene Ormandy and Arturo Toscanini, are given on CBS and NBC.

1948    U.S. President Harry S. Truman issues a peacetime military draft in the United States amid increasing tensions with the Soviet Union.

1949    Point Four Program a program for economic aid to poor countries announced by United States President Harry S. Truman in his inaugural address for a full term as President.

1949    A fire in a hospital in Effingham, Illinois, kills 77 people and leads to nationwide fire code improvements in the United States.

1949    The National Basketball Association is founded in the United States.

1950    The United States decides to send troops to fight in the Korean War.

1950    Edith Sampson becomes the first black U.S. delegate to the United Nations.

1950    Korean War: United States forces land at Inchon

1950    Paula Ackerman, the first woman appointed to perform rabbinical functions in the United States, leads the congregation in her first services.

1951    The United States, Australia and New Zealand sign a mutual defense pact, called the ANZUS Treaty.

1951    The first live sporting event seen coast-to-coast in the United States, a college football game between Duke and the University of Pittsburgh, is televised on NBC.

1951    Operation Buster-Jangle: 6,500 American soldiers are exposed to 'Desert Rock' atomic explosions for training purposes in Nevada. Participation is not voluntary.

1951    Direct-dial coast-to-coast telephone service begins in the United States.

1952    President Harry Truman announces that the United States has developed the hydrogen bomb.

1952    The United States government establishes the National Security Agency.

1953    Censorship: Georgia approves the first literature censorship board in the United States.

1953    Nuclear testing: At the Nevada Test Site, the United States conduct their first and only nuclear artillery test.

1953    The Korean War ends when the United States, the People's Republic of China, and North Korea sign an armistice agreement. Syngman Rhee, President of South Korea, refuses to sign but pledges to observe the armistice.

1953    Cold War: U.S. President Dwight D. Eisenhower formally approves the top secret document National Security Council Paper No. 162/2, which states that the United States' arsenal of nuclear weapons must be maintained and expanded to counter the communist threat.

1954    President Dwight Eisenhower warns against United States intervention in Vietnam.

1954    Nuclear testing: The Castle Bravo, a 15-megaton hydrogen bomb, is detonated on Bikini Atoll in the Pacific Ocean, resulting in the worst radioactive contamination ever caused by the United States.

1954    U.S. President Dwight D. Eisenhower signs a bill into law that places the words "under God" into the U.S. Pledge of Allegiance.

1954    Dwight D. Eisenhower pledges United States support to South Vietnam

1954    In Sylacauga, Alabama, United States, the Hodges Meteorite crashes through a roof and hits a woman taking an afternoon nap in the only documented case of a human being hit by a rock from space.

1954    The Sino-American Mutual Defense Treaty, between the United States and the Republic of China, is signed in Washington, D.C..

1954    The first Burger King is opened in Miami, Florida, United States

1955    ''Sam and Friends'' debuts on a local United States television channel, marking the first television appearance of both Jim Henson and what would become Kermit the Frog and The Muppets.

1956    In Operation Redwing (shot ''Cherokee''), the first United States airborne hydrogen bomb is dropped over Bikini Atoll in the Pacific Ocean;

1956    The Federal-Aid Highway Act of 1956 is signed, officially creating the United States Interstate Highway System.

1956    A joint resolution of the U.S. Congress is signed by President Dwight D. Eisenhower, authorizing ''In God We Trust'' as the U.S. national motto.

1956    After going bankrupt in 1955, the American broadcaster DuMont Television Network makes its final broadcast, a boxing match from St. Nicholas Arena in New York in the ''Boxing from St. Nicholas Arena'' series.

1957    The United States and Canada form the North American Air Defense Command (NORAD).

1957    Vietnam War: First United States casualties in Vietnam.

1957    Cold War: The Gaither Report calls for more American missiles and fallout shelters.

1957    Project Vanguard: A launchpad explosion of Vanguard TV3 thwarts the first United States attempt to launch a satellite into Earth orbit.

1957    The United States successfully launches the first Atlas intercontinental ballistic missile at Cape Canaveral, Florida.

1958    Explorer program: ''Explorer 1'' – The first successful launch of an American satellite into orbit.

1958    Samuel Alphonsus Stritch is appointed Pro-Prefect of the Propagation of Faith and thus becomes the first American member of the Roman Curia.

1958    A United States federal court rules that poet Ezra Pound is to be released from an insane asylum.

1958    The John Birch Society was founded in the United States.

1959    The steel strike of 1959 begins, leading to significant importation of foreign steel for the first time in United States history.

1959    First United States Congress elections in Hawaii as a state of the Union.

1959    Nikita Khrushchev becomes the first Soviet leader to visit the United States.

1960    Belgium defends its intervention in the Congo to the United Nations Security Council while the government of the Congo appeals to the Soviet Union to send troops to push back the Belgians. The governments of the United States and France and the North Atlantic Treaty Organization warn the Soviets to stay out of the dispute.

1960    Cuban Revolution: in response to a United States embargo, Cuba nationalizes American and foreign-owned property in the nation.

1961    Sabena Flight 548 crashes in Belgium, killing 73, including the entire United States figure skating team, several coaches and family.

1961    United States President John F. Kennedy sends 18,000 military advisors to South Vietnam.

1962    The United States bans all Cuban imports and exports.

1962    Captured American U2 spy-plane pilot Gary Powers is exchanged for captured Soviet spy Rudolf Abel.

1962    The Old Bay Line, the last overnight steamboat service in the United States, goes out of business.

1962    Cuban Missile Crisis between the United States and Cuba begins.

1963    Travel, financial and commercial transactions by United States citizens to Cuba are made illegal by the John F. Kennedy administration.

1963    The United States, the United Kingdom, and the Soviet Union sign a nuclear test ban treaty.

1963    The Hotline between the leaders of the U.S.A. and the Soviet Union goes into operation.

1963    ''CBS Evening News'' becomes U.S. network television's first half-hour weeknight news broadcast, when the show is lengthened from 15 to 30 minutes.

1963    The 16th Street Baptist Church bombing: Four children killed at an African-American church in Birmingham, Alabama, United States

1963    Vietnam War: Newly sworn-in US President Lyndon B. Johnson confirms that the United States intends to continue supporting South Vietnam both militarily and economically.

1964    U.S. President Lyndon B. Johnson announces the goals of his Great Society social reforms to bring an "end to poverty and racial injustice" in America.

1964    Vietnam War: 5,000 more American military advisers are sent to South Vietnam bringing the total number of United States forces in Vietnam to 21,000.

1964    Gulf of Tonkin Incident: U.S. destroyers {{USS|Maddox|DD-731|6}} and {{USS|Turner Joy|DD-951|6}} report coming under attack in the Gulf of Tonkin.

1964    Vietnam War: the U.S. Congress passes the Gulf of Tonkin Resolution giving US President Lyndon B. Johnson broad war powers to deal with North Vietnamese attacks on American forces.

1964    Cold War: Indian Prime Minister Jawaharlal Nehru appeals to the United States and the Soviet Union to end nuclear testing and to start nuclear disarmament, stating that such an action would "save humanity from the ultimate disaster".

1965    Vietnam War: The first United States combat troops are sent to South Vietnam.

1965    NASA launches Gemini 3, the United States' first two-man space flight (crew: Gus Grissom and John Young).

1965    Vietnam War: The United States uses B-52 bombers to attack National Liberation Front guerrilla fighters in South Vietnam.

1965    Cuba and the United States formally agree to begin an airlift for Cubans who want to go to the United States. By 1971, 250,000 Cubans made use of this program.

1965    Vietnam War: The Battle of the Ia Drang begins – the first major engagement between regular American and North Vietnamese forces.

1965    Vietnam War: The Pentagon tells U.S. President Lyndon B. Johnson that if planned operations are to succeed, the number of American troops in Vietnam has to be increased from 120,000 to 400,000.

1966    Lyndon B. Johnson states that the United States should stay in South Vietnam until Communist aggression there is ended.

1966    Launch of Gemini 8, the 12th manned American space flight and first space docking with the Agena Target Vehicle.

1966    The Cuban Adjustment Act enters force, allowing 123,000 Cubans the opportunity to apply for permanent residence in the United States.

1967    American researchers discover the Madrid Codices by Leonardo da Vinci in the National Library of Spain.

1967    Joseph Stalin's daughter Svetlana Alliluyeva defects to the United States.

1967    Vietnam War: off the coast of North Vietnam the {{USS|Forrestal|CV-59|6}} catches on fire in the worst U.S. naval disaster since World War II, killing 134.

1967    Vietnam War: Operation Swift begins: U.S. Marines engage the North Vietnamese in battle in the Que Son Valley.

1967    Vietnam War: In a propaganda ceremony in Phnom Penh, Cambodia, three American prisoners of war are released by the Viet Cong and turned over to "new left" antiwar activist Tom Hayden.

1967    Vietnam War: American General William Westmoreland tells news reporters: "I am absolutely certain that whereas in 1965 the enemy was winning, today he is certainly losing."

1967    Vietnam War: US and South Vietnamese forces engage Viet Cong troops in the Mekong Delta.

1968    Viet Cong attack the United States embassy in Saigon, and other attacks, in the early morning hours, later grouped together as the Tet Offensive.

1968    United States athletes Tommie Smith and John Carlos are kicked off the USA's team for participating in the 1968 Olympics Black Power salute.

1969    Vietnam War: U.S. President Richard Nixon declares the Nixon Doctrine, stating that the United States now expects its Asian allies to take care of their own military defense. This is the start of the "Vietnamization" of the war.

1969    Vietnam War: US President Richard M. Nixon makes an unscheduled visit to South Vietnam and meets with President Nguyễn Văn Thiệu and U.S. military commanders.

1969    Vietnam War: at the apartment of French intermediary Jean Sainteny in Paris, American representative Henry Kissinger and North Vietnamese representative Xuan Thuy begin secret peace negotiations. The negotiations will eventually fail.

1969    National Educational Television (the predecessor to the Public Broadcasting Service) in the United States debuts the children's television program ''Sesame Street''.

1969    Cold War: Negotiators from the Soviet Union and the United States meet in Helsinki to begin SALT I negotiations aimed at limiting the number of strategic weapons on both sides.

1970    President Richard Nixon signs the Public Health Cigarette Smoking Act into law, requiring the Surgeon General's warnings on tobacco products and banning cigarette advertisements on television and radio in the United States, starting on January 1, 1971.

1970    Vietnam War: US President Richard Nixon announces that the United States will withdraw 40,000 more troops before Christmas

1970    Vietnam War: The United States Military Assistance Command in Vietnam reports the lowest weekly American soldier death toll in five years (24).

1971    Cigarette advertisements are banned on American television.

1971    The Winter Soldier Investigation, organized by the Vietnam Veterans Against the War to publicize war crimes and atrocities by Americans and allies in Vietnam, begin in Detroit, Michigan.

1971    Eighty-seven countries, including the US, UK, and USSR, sign the Seabed Treaty outlawing nuclear weapons in international waters.

1971    Vietnam War: Backed by American air and artillery support, South Vietnamese troops invade Laos.

1971    Walt Disney World opens near Orlando, Florida, United States.

1971    Sold, dismantled and moved to the United States, London Bridge reopens in Lake Havasu City, Arizona.

1971    Vietnam War: As part of Vietnamization, US President Richard M. Nixon sets February 1, 1972 as the deadline for the removal of another 45,000 American troops from Vietnam.

1971    The Libertarian Party of the United States is formed.

1972    Sound recordings are granted U.S. federal copyright protection for the first time.

1972    Sino-American relations: The United States and People's Republic of China sign the Shanghai Communiqué.

1972    Vietnam War: Increased American bombing in Vietnam prompts anti-war protests in Los Angeles, New York City, and San Francisco.

1972    The United States launch ''Landsat 1'', the first Earth-resources satellite.

1972    Vietnam War: the last United States ground combat unit departs South Vietnam.

1972    In Reykjavík, Iceland, American Bobby Fischer beats Russian Boris Spassky and becomes the world chess champion.

1972    The United States suffers its first loss of an international basketball game in a disputed match against the Soviet Union at Munich, Germany.

1972    Vietnam War: In Saigon, Henry Kissinger and South Vietnamese President Nguyen Van Thieu meet to discuss a proposed cease-fire that had been worked out between Americans and North Vietnamese in Paris.

1972    Vietnam War: White House Press Secretary Ron Ziegler tells the press that there will be no more public announcements concerning American troop withdrawals from Vietnam due to the fact that troop levels are now down to 27,000.

1972    Vietnam War: President Richard Nixon announces that the United States will engage North Vietnam in Operation Linebacker II, a series of Christmas bombings, after peace talks collapsed with North Vietnam on the 13th.

1972    Vietnam War: The United States halts heavy bombing of North Vietnam.

1973    Vietnam War: First release of American prisoners of war from Vietnam takes place.

1973    Vietnam War: The first United States prisoners of war are released by the Viet Cong.

1973    The first portable cell phone call is made in New York City, United States.

1973    A fire destroys the entire 6th floor of the National Personnel Records Center of the United States.

1973    Vietnam War: The United States bombing of Cambodia ends.

1973    The Endangered Species Act is passed in the United States.

1974    In response to the 1973 energy crisis, daylight saving time commences nearly four months early in the United States.

1974    After 84 days in space, the crew of the first American space station Skylab returns to Earth.

1974    After seven years, the United States and Egypt re-establish diplomatic relations.

1974    Western Union (in cooperation with NASA and Hughes Aircraft) launches the United States' first commercial geosynchronous communications satellite, Westar 1.

1974    Turkish occupation of Cyprus: Forces from Turkey invade Cyprus after a "coup d' etat", organised by the dictator of Greece, against president Makarios. NATO's Council praises the United States and the United Kingdom for attempts to settle the dispute. Syria and Egypt put their militaries on alert.

1974    Franklin National Bank collapses due to fraud and mismanagement; at the time it is the largest bank failure in the history of the United States.

1975    The Japanese Red Army takes more than 50 hostages at the AIA Building housing several embassies in Kuala Lumpur, Malaysia. The hostages include the U.S. consul and the Swedish chargé d’affaires. The gunmen win the release of five imprisoned comrades and fly with them to Libya.

1975    The first American saint, Elizabeth Ann Seton, is canonized by Pope Paul VI.

1976    The Groundhog Day gale hits the north-eastern United States and south-eastern Canada.

1976    Cold War: Soviet air force pilot Lt. Viktor Belenko lands a MiG-25 jet fighter at Hakodate on the island of Hokkaidō in Japan and requests political asylum in the United States.

1977    President Jimmy Carter pardons nearly all American Vietnam War draft evaders, some of whom had emigrated to Canada.

1977    The Torrijos-Carter Treaties between Panama and the United States on the status of the Panama Canal are signed. The United States agrees to transfer control of the canal to Panama at the end of the 20th century.

1977    The Torrijos-Carter Treaties between Panama and the United States on the status of the Panama Canal are signed. The United States agrees to transfer control of the canal to Panama at the end of the 20th century.

1978    Director Roman Polanski skips bail and flees the United States to France after pleading guilty to charges of engaging in sex with a 13-year-old girl.

1978    U.S. President Jimmy Carter announces that the United States will recognize the People's Republic of China and cut off all relations with Taiwan

1979    Formal diplomatic relations are established between the People's Republic of China and the United States of America.

1979    In Kabul, Muslims kidnap the American ambassador to Afghanistan, Adolph Dubs who is later killed during a gunfight between his kidnappers and police.

1979    SALT II is signed by the United States and the Soviet Union.

1979    U.S. President Jimmy Carter gives his so-called "malaise" speech, where he characterizes the greatest threat to the country as "this crisis in the growing doubt about the meaning of our own lives and in the loss of a unity of purpose for our nation" but in which he never uses the word ''malaise''

1979    Soviet dancer Alexander Godunov defects to the United States.

1979    The Chrysler Corporation asks the United States government for USD $1.5 billion to avoid bankruptcy.

1979    The United States returns sovereignty of the Panama canal to Panama.

1979    Iran hostage crisis begins: a group of Iranians, mostly students, invades the US embassy in Tehran and takes 90 hostages (53 of whom are American).

1979    Iran hostage crisis: In response to the hostage situation in Tehran, US President Jimmy Carter orders a halt to all petroleum imports into the United States from Iran.

1979    Iran hostage crisis: US President Jimmy Carter issues Executive order 12170, freezing all Iranian assets in the United States in response to the hostage crisis.

1979    Iran hostage crisis: Iranian leader Ayatollah Ruhollah Khomeini orders the release of 13 female and black American hostages being held at the US Embassy in Tehran.

1979    The United States Embassy in Islamabad, Pakistan is attacked by a mob and set on fire, killing four. (see: Foreign relations of Pakistan)

1979    Libya joins four other OPEC nations in raising crude oil prices, having an immediate dramatic effect on the United States.

1980    Through cooperation between the U.S. and Canadian governments, six American diplomats secretly escape hostilities in Iran in the culmination of the Canadian caper.

1980    US President Jimmy Carter announces a United States boycott of the 1980 Summer Olympics in Moscow to protest the Soviet Invasion of Afghanistan.

1980    1980 eruption of Mount St. Helens: Mount St. Helens erupts in Washington, United States, killing 57 people and causing $3 billion in damage.

1981    The Republic of Palau achieves self-government though it is not independent from the United States.

1981    Tehran releases American hostages after 444 days.

1981    Cold War: In Geneva, representatives from the United States and the Soviet Union begin to negotiate intermediate-range nuclear weapon reductions in Europe (the meetings ended inconclusively on December 17).

1982    "Cold Sunday" in the United States would see temperatures fall to their lowest levels in over 100 years in numerous cities.

1982    EPCOT Center opens at Walt Disney World near Orlando, Florida, United States.

1982    In Texas, Charles Brooks, Jr. becomes the first person to be executed by lethal injection in the United States.

1983    Thirteen people die and one is seriously injured in the Wah Mee Massacre in Seattle, Washington. It is said to be the largest robbery-motivated mass-murder in U.S. history.

1983    American schoolgirl Samantha Smith is invited to visit the Soviet Union by its leader Yuri Andropov after he read her letter in which she expressed fears about nuclear war.

1983    Lebanon, Israel, and the United States sign an agreement on Israeli withdrawal from Lebanon.

1983    Space Shuttle program: STS-7, Astronaut Sally Ride becomes the first American woman in space.

1983    Cold War: Samantha Smith, a U.S. schoolgirl, flies to the Soviet Union at the invitation of Secretary General Yuri Andropov.

1983    A Wells Fargo depot in West Hartford, Connecticut, United States, is robbed of approximately US$7 million by Los Macheteros.

1983    Operation Urgent Fury: The United States and its Caribbean allies invade Grenada, six days after Prime Minister Maurice Bishop and several of his supporters are executed in a coup d'état.

1984    The United States and the Vatican establish full diplomatic relations after 117 years.

1984    Aboard the Space Shuttle ''Challenger'', astronaut Kathryn D. Sullivan becomes the first American woman to perform a space walk.

1984    Capital punishment: Velma Barfield becomes the first woman executed in the United States since 1962.

1985    The Food and Drug Administration approves a blood test for AIDS, used since then for screening all blood donations in the United States.

1985    United States Vice President George H.W. Bush becomes the Acting President for the day when President Ronald Reagan undergoes surgery to remove polyps from his colon.

1985    A joint American–French expedition locates the wreckage of the {{RMS|Titanic}}.

1985    Free Software Foundation is founded in Massachusetts, United States.

1986    The United States launches Operation El Dorado Canyon, its bombing raids against Libyan targets in response to a bombing in West Germany that killed two U.S. servicemen.

1986    In Lebanon, pro-Iranian kidnappers claim to have abducted American writer Edward Tracy (he is released in August 1991).

1986    Iran-Contra Affair: The Lebanese magazine ''Ash-Shiraa'' reports that the United States has been secretly selling weapons to Iran in order to secure the release of seven American hostages held by pro-Iranian groups in Lebanon.

1987    The U.S. Department of Justice bars the Austrian President Kurt Waldheim from entering the United States, saying he had aided in the deportation and execution of thousands of Jews and others as a German Army officer during World War II.

1988    The Evangelical Lutheran Church in America comes into existence, creating the largest Lutheran denomination in the United States.

1988    A report by United States' Surgeon General C. Everett Koop states that the addictive properties of nicotine are similar to those of heroin and cocaine.

1988    Japanese American internment: U.S. President Ronald Reagan signs the Civil Liberties Act of 1988, providing $20,000 payments to Japanese Americans who were either interned in or relocated by the United States during World War II.

1988    U.S. televangelist Jim Bakker is indicted for fraud.

1989    Ron Brown is elected chairman of the Democratic National Committee becoming the first African American to lead a major American political party.

1989    The United States becomes a member of the Berne Convention for the Protection of Literary and Artistic Works.

1989    Douglas Wilder wins the governor's seat in Virginia, becoming the first elected African American governor in the United States.

1989    The first episode of television series ''The Simpsons'', "Simpsons Roasting on an Open Fire", airs in the United States.

1989    United States invasion of Panama: The United States sends troops into Panama to overthrow government of Manuel Noriega.

1991    Gulf War: An Iraqi scud missile hits an American military barracks in Dhahran, Saudi Arabia killing 28 U.S. Army Reservists from Pennsylvania.

1991    Seventy tornadoes break out in the central United States. Before the outbreak's end, Andover, Kansas, would record the year's only F5 tornado (see Andover, Kansas Tornado Outbreak).

1991    The United States recognize the independence of the Baltic states: Estonia, Latvia, and Lithuania.

1991    The trial of the deposed Panamanian dictator Manuel Noriega begins in the United States.

1992    Boris Yeltsin announces that Russia will stop targeting United States cities with nuclear weapons.

1992    The United States Supreme Court rules in ''United States v. Álvarez-Machaín'' that it is permissible for the USA to forcibly extradite suspects in foreign countries and bring them to the USA for trial, without approval from those other countries.

1992    Near Medellín, Colombian drug lord Pablo Escobar escapes from his luxury prison fearing extradition to the United States.

1992    Hurricane Iniki, one of the most damaging hurricanes in United States history, devastates Hawaii.

1992    UN Security Council Resolution 794 is unanimously passed, approving a coalition of United Nations peacekeepers led by the United States to form UNITAF, with the task of establishing peace and ensuring that humanitarian aid is distributed in Somalia.

1992    Somali Civil War: President George H. W. Bush orders 28,000 US troops to Somalia in Northeast Africa.

1993    The 51-day siege of the Branch Davidian building outside Waco, Texas, USA, ends when a fire breaks out. Eighty-one people die.

1993    In the United States, the North American Free Trade Agreement (NAFTA) is ratified by the House of Representatives.

1994    North Korea nuclear weapons program: North Korea and the United States sign an agreement that requires North Korea to stop its nuclear weapons program and agree to inspections.

1995    Oklahoma City bombing: The Alfred P. Murrah Federal Building in Oklahoma City, Oklahoma, USA, is bombed, killing 168. That same day convicted murderer Richard Wayne Snell, who had ties to one of the bombers, Timothy McVeigh, is executed in Arkansas.

1995    Full diplomatic relations are established between the United States and Vietnam.

1995    A truck-bomb explodes outside of a US-operated Saudi Arabian National Guard training center in Riyadh, killing five Americans and two Indians. A group called the Islamic Movement for Change claims responsibility.

1996    Major snowstorm paralyzes Midwestern United States, Milwaukee, Wisconsin ties all-time record low temperature at -26°F (-32.2°C)

1996    Suspected "Unabomber" Theodore Kaczynski is arrested at his cabin in Montana, United States.

1996    Osama bin Laden issues message entitled 'A declaration of war against the Americans occupying the land of the two holy places.'

1997    United States media magnate Ted Turner donates USD $1 billion to the United Nations.

1997    In Ottawa, Canada, representatives from 121 countries sign The Ottawa treaty prohibiting manufacture and deployment of anti-personnel landmines. The United States, People's Republic of China, and Russia do not sign the treaty, however.

1998    A massive ice storm hits eastern Canada and the northeastern United States, continuing through January 10 and causing widespread destruction.

1998    Lewinsky scandal: On American television, U.S. President Bill Clinton denies having had "sexual relations" with former White House intern Monica Lewinsky.

1998    Karla Faye Tucker is executed in Texas becoming the first woman executed in the United States since 1984.

1998    Disney's Animal Kingdom opens at Walt Disney World near Orlando, Florida, United States.

1998    Nuclear testing: Pakistan responds to a series of nuclear tests by India with five of its own, prompting the United States, Japan, and other nations to impose economic sanctions.

1998    Japan launches a probe to Mars, and thus joins the United States and Russia as a space exploring nation.

1998    U.S. embassy bombings: the United States launches cruise missile attacks against alleged al-Qaida camps in Afghanistan and a suspected chemical plant in Sudan in retaliation for the August 7 bombings of American embassies in Kenya and Tanzania.

1998    Brokerage houses are ordered to pay 1.03 billion USD to cheated NASDAQ investors to compensate for their price-fixing. This is the largest civil settlement in United States history.

1999    The World Trade Organisation rules in favor of the United States in its long-running trade dispute with the European Union over bananas.

1999    In Seattle, Washington, United States, protests against the WTO meeting by anti-globalization protesters catch police unprepared and force the cancellation of opening ceremonies.

1999    The United States Government hands control of the Panama Canal (as well all the adjacent land to the canal known as the Panama Canal Zone) to Panama. This act complied with the signing of the 1977 Torrijos-Carter Treaties.

2001    The American submarine {{USS|Greeneville|SSN-772|6}} accidentally strikes and sinks the ''Ehime-Maru'', a Japanese training vessel operated by the Uwajima Fishery High School.

2001    The September 11 attacks take place in the United States. Airplane hijackings result in the collapse of the World Trade Center in New York City, damage to The Pentagon in Arlington, Virginia, and the crashing of a passenger airliner in Shanksville, Pennsylvania.

2001    Civilian aircraft traffic resumes in the U.S. after the September 11, 2001 attacks.

2001    The United States passes the USA PATRIOT Act into law.

2001    War on Terrorism: In the first such act since World War II, US President George W. Bush signs an executive order allowing military tribunals against foreigners suspected of connections to terrorist acts or planned acts on the United States.

2001    The People's Republic of China is granted permanent normal trade relations with the United States.

2002    Kmart becomes the largest retailer in United States history to file for Chapter 11 bankruptcy protection.

2002    "American Taliban" John Walker Lindh returns to the United States in FBI custody.

2002    US Secretary of Energy makes the decision that Yucca Mountain is a suitable site for a deep geological repository for the United States.

2002    The United States of America withdraws from the Anti-Ballistic Missile Treaty.

2002    Iran bans advertising of United States products.

2003    United States President George W. Bush orders the start of war against Iraq.

2003    2003 invasion of Iraq: In the early hours of the morning, the United States and three other countries begin military operations in Iraq.

2003    The Arab League votes 21-1 in favor of a resolution demanding the immediate and unconditional removal of U.S. and British soldiers from Iraq.

2003    In a "friendly fire" incident, two A-10 Thunderbolt II attack aircraft from the United States Idaho Air National Guard's 190th Fighter Squadron attack British tanks participating in the 2003 invasion of Iraq, killing British soldier Matty Hull.

2003    2003 invasion of Iraq: Baghdad falls to American forces;Saddam Hussein statue topples as Iraqis turn on symbols of their former leader, pulling down the statue and tearing it to pieces.

2003    Members of 101st Airborne of the United States, aided by Special Forces, attack a compound in Iraq, killing Saddam Hussein's sons Uday and Qusay, along with Mustapha Hussein, Qusay's 14-year old son, and a bodyguard.

2003    Widescale power blackout in the northeast United States and Canada.

2004    The United States lifts a ban on travel to Libya, ending travel restrictions to the nation that had lasted for 23 years.

2004    Massachusetts becomes the first U.S. state to legalize same-sex marriage.

2004    Sovereign power is handed to the interim government of Iraq by the Coalition Provisional Authority, ending the U.S.-led rule of that nation.

2004    War in Iraq: More than 10,000 U.S. troops and a small number of Iraqi army units participate in a siege on the insurgent stronghold of Fallujah.

2005    Hurricane Rita makes landfall in the United States, devastating Beaumont, Texas and portions of southwestern Louisiana.

2006    Scotland Yard disrupts a major terrorist plot to destroy aircraft traveling from the United Kingdom to the United States.

2006    The United States population reaches 300 million.

2006    The International Conference to Review the Global Vision of the Holocaust is opened in Tehran, Iran by Mahmoud Ahmadinejad; Nations such as Israel and the United States express concern.

2010    John Isner of the United States defeats Nicolas Mahut of France at Wimbledon, in the longest match in tennis history.

2010    Operation Iraqi Freedom ends, with the last of the United States brigade combat teams crossing the border to Kuwait.