On what date were the United States Constitution’s 1787 delegates gathered to sign the final document?

The United States Constitution was signed on September 17, 1787.

The signing took place at Independence Hall in Philadelphia at the close of the Constitutional Convention. Delegates had met for four months to design a stronger federal system after concluding that the Articles of Confederation were too weak to manage the country effectively.

George Washington, who presided over the convention, signed first. In total, 39 delegates endorsed the final document, representing twelve states. Rhode Island did not send delegates to the convention, and several delegates who attended refused to sign.

Signing did not immediately make the Constitution law. The document required ratification by nine states, which occurred on June 21, 1788, when New Hampshire approved it. The new federal government began operating on March 4, 1789, and George Washington took the first presidential oath on April 30 of that year.