On what date was the United States Constitution signed at Independence Hall, a key America250 landmark?

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

The signing concluded the Constitutional Convention in Philadelphia, which had met from May 25 to September 17. The convention was originally called to revise the Articles of Confederation, but its delegates produced an entirely new framework for the federal government.

Thirty-nine delegates signed the document, representing 12 states. Rhode Island declined to send delegates to the convention. George Washington, who presided over the convention, signed first. Three delegates present—George Mason, Edmund Randolph, and Elbridge Gerry—refused to sign because they objected to aspects of the proposed system.

The signing date is distinct from the Constitution’s ratification date and its effective date. New Hampshire became the ninth state to ratify on June 21, 1788, while the new federal government began operating under the Constitution on March 4, 1789.