1791 Vermont is admitted as the 14th U.S. state.
1803 Ohio is admitted as the 17th U.S. state.
1812 The Territory of Orleans becomes the 18th U.S. state under the name Louisiana.
1816 Indiana becomes the 19th U.S. state.
1817 Mississippi becomes the 20th U.S. state.
1818 Illinois becomes the 21st U.S. state.
1819 Alabama becomes the 22nd U.S. state.
1820 Maine becomes the 23rd U.S. state.
1821 Missouri is admitted as the 24th U.S. state.
1836 Arkansas is admitted as the 25th U.S. state.
1837 Michigan is admitted as the 26th U.S. state.
1845 Florida is admitted as the 27th U.S. state.
1845 According with International Boundary delimitation, U.S.A annexes the Mexican state of Texas, following the Manifest Destiny doctrine. For others, the Republic of Texas is admitted as the 28th U.S. state.
1846 Iowa is admitted as the 29th U.S. state.
1848 Mexican-American War: Mexico ratifies the Treaty of Guadalupe Hidalgo thus ending the war and ceding California, Nevada, Utah and parts of four other modern-day U.S. states to the United States for $15 million USD.
1848 Wisconsin is admitted as the 30th U.S. state.
1850 California is admitted as the thirty-first U.S. state.
1859 Oregon is admitted as the 33rd U.S. state.
1861 Kansas is admitted as the 34th U.S. state.
1864 Nevada is admitted as the 36th U.S. state.
1876 Colorado is admitted as the 38th U.S. state.
1889 Montana is admitted as the 41st U.S. state.
1889 Washington is admitted as the 42nd U.S. state.
1890 Idaho is admitted as the 43rd U.S. state.
1890 Wyoming is admitted as the 44th U.S. state.
1893 Women in the U.S. state of Colorado are granted the right to vote.
1896 Utah is admitted as the 45th U.S. state.
1912 New Mexico is admitted as the 47th U.S. state.
1912 Arizona is admitted as the 48th U.S. state.
1929 JC Penney opens store #1252 in Milford, Delaware, making it a nationwide company with stores in all 48 U.S. states.
1933 Prohibition in the United States ends: Utah becomes the 36th U.S. state to ratify the Twenty-first Amendment to the United States Constitution, thus establishing the required 75% of states needed to enact the amendment (this overturned the 18th Amendment which had made the manufacture, sale, or transportation of alcohol illegal in the United States).
1960 Due to the post-Independence Day admission of Hawaii as the 50th U.S. state on August 21, 1959, the 50-star flag of the United States debuts in Philadelphia, Pennsylvania almost ten and a half months later (see Flag Act).
1998 Voters in Maine repeal a gay rights law passed in 1997 becoming the first U.S. state to abandon such a law.