At the 1787 signing of the United States Constitution, 39 delegates added their signatures.
The signing took place on September 17, 1787, at Independence Hall in Philadelphia, Pennsylvania. The Constitutional Convention had met to replace the Articles of Confederation with a stronger national framework. Although 74 delegates had been selected, only 55 attended the convention, and three of those present at the end declined to sign.
The 39 signers represented 12 states. Rhode Island did not send delegates to the convention. George Washington, who presided over the gathering, signed first, and Benjamin Franklin was the oldest signer at age 81. The completed document was then sent to the Confederation Congress for submission to the states.
A common mix-up is to confuse the 39 signers with the 55 delegates who attended at some point. The Constitution also did not take effect simply because it was signed: Article Seven required ratification by nine states.