Delegates signed the U.S. Constitution on September 17, 1787, a date from the era commemorated by America250.
The Constitutional Convention met in Philadelphia during the summer of 1787 to revise the Articles of Confederation, but it ultimately produced an entirely new framework of government. Thirty-nine delegates signed the finished Constitution on September 17 before it was sent to the states for ratification.
The signing date is different from the dates associated with the Declaration of Independence. Congress adopted the Declaration on July 4, 1776, and most delegates signed its engrossed parchment on August 2, 1776. The Constitution became operative after New Hampshire supplied the ninth ratification on June 21, 1788.
Not every delegate who attended the convention signed. Three delegates—George Mason, Edmund Randolph, and Elbridge Gerry—refused to sign, while some others had already left Philadelphia. George Washington, president of the convention, signed the Constitution and later became the first U.S. president under its new government.