1787 In Philadelphia, Pennsylvania, delegates convene a Constitutional Convention to write a new Constitution for the United States; George Washington presides.
1787 Sixty proof sheets of the Constitution of the United States are delivered to the Constitutional Convention in Philadelphia.
1787 The United States Constitution is signed in Philadelphia, Pennsylvania.
1787 The newly completed United States Constitution is voted on by the U.S. Congress to be sent to the state legislatures for approval.
1787 Delaware becomes the first state to ratify the United States Constitution.
1787 Pennsylvania becomes the second state to ratify the United States Constitution five days after Delaware became the first.
1787 New Jersey becomes the third state to ratify the U.S. Constitution.
1788 Georgia becomes the fourth state to ratify the United States Constitution
1788 Massachusetts becomes the sixth state to ratify the United States Constitution.
1788 Virginia becomes the 10th state to ratify the United States Constitution.
1788 New York ratifies the United States Constitution and becomes the 11th state of the United States.
1789 In New York City, the first Congress of the United States meets, putting the United States Constitution into effect.
1789 The U.S. Congress passes twelve amendments to the United States Constitution: the Congressional Apportionment Amendment (which was never ratified), the Congressional Compensation Amendment, and the ten that are known as the Bill of Rights.
1789 North Carolina ratifies the United States Constitution and is admitted as the 12th U.S. state.
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.
1795 The 11th Amendment to the United States Constitution is ratified.
1803 Chief Justice John Marshall declares that any act of U.S. Congress that conflicts with the Constitution is void.
1909 U.S. President William Taft used what became known as a '''Saxbe fix''', a mechanism to avoid the restriction of the U.S. Constitution's Ineligibility Clause, to appoint Philander C. Knox as U.S. Secretary of State
1920 The 19th amendment to United States Constitution takes effect, giving women the right to vote.
1964 The 24th Amendment to the United States Constitution, prohibiting the use of poll taxes in national elections, is ratified.
1992 Michigan ratifies a 203-year-old proposed amendment to the United States Constitution making the 27th Amendment law. This amendment bars the U.S. Congress from giving itself a mid-term pay raise.
1998 In ''Clinton v. City of New York'', the United States Supreme Court decides that the Line Item Veto Act of 1996 is unconstitutional.