Thirty-nine delegates endorsed the United States Constitution at its signing in 1787.
The signing took place on September 17, 1787, at Independence Hall in Philadelphia. The delegates represented 12 states; Rhode Island had declined to send representatives to the Constitutional Convention. The convention had originally involved more delegates, but not everyone who attended agreed to sign the final document.
The Constitution’s closing endorsement stated that the convention’s work had been completed and that the participating delegates subscribed to the document. Among those who refused to sign were George Mason, Edmund Randolph, and Elbridge Gerry, who had concerns about the document’s structure or its lack of a bill of rights.
The 39 signatures did not by themselves ratify the Constitution. Ratification required approval by conventions in nine states under Article VII. New Hampshire became the ninth state to ratify on June 21, 1788, allowing the new federal government to proceed.