Thirty-nine delegates signed the United States Constitution, a later milestone in America's founding story.
The signing took place on September 17, 1787, at the Pennsylvania State House in Philadelphia, now called Independence Hall. The delegates had spent roughly four months debating how to replace the Articles of Confederation with a stronger federal framework.
Fifty-five delegates attended the Constitutional Convention at some point, but only 39 signed the finished document. Three delegates who remained at the convention refused to sign, while others had already departed. Rhode Island did not send delegates to the convention.
The Constitution was then sent to the states for ratification. Article VII required approval by nine states, and New Hampshire became the ninth state to ratify on June 21, 1788. The new federal government began operating in 1789.