Thirty-nine delegates signed the United States Constitution in 1787.
The signing took place on September 17 at Independence Hall in Philadelphia, after the Constitutional Convention had worked for four months. The 39 signers represented 12 states; Rhode Island declined to send delegates to the convention. George Washington, serving as convention president, signed first.
The number of signers is different from the number of delegates chosen or attending. Seventy-four delegates were selected, 55 attended at some point, and 39 ultimately signed. Three delegates who remained at the convention declined to sign: Edmund Randolph, George Mason, and Elbridge Gerry.
The Constitution created the framework for the federal government, including its legislative, executive, and judicial branches. It was not the document adopted in 1776, and it did not itself declare independence. Its signing was a later stage in the creation of the United States, making it a useful neighboring milestone for understanding the history commemorated by America250.