On what date was the U.S. Constitution signed, the 1787 document remembered during America250?

The U.S. Constitution was signed on September 17, 1787, the date associated with the 1787 document remembered during America250.

Delegates to the Constitutional Convention met in Philadelphia from May through September 1787. On September 17, thirty-nine delegates signed the completed Constitution at the Pennsylvania State House, now Independence Hall. George Washington, who presided over the convention, signed first.

The signing did not immediately create a functioning government. Article Seven sent the Constitution to the states for ratification, and nine states had to approve it before it could take effect. New Hampshire became the ninth state to ratify on June 21, 1788, while the new federal government began operating in 1789.

September 17 is now observed in the United States as Constitution Day and Citizenship Day. It is distinct from July 4, 1776, the adoption date of the Declaration of Independence, and from December 7, 1787, Delaware’s ratification date.