Delegates signed the U.S. Constitution at the Philadelphia Convention on September 17, 1787, a milestone linked to America250.
The signing took place at Independence Hall in Philadelphia after the Constitutional Convention’s four-month deliberation. Thirty-nine delegates endorsed the document, representing 12 states; Rhode Island had declined to send delegates. George Washington, the convention’s presiding officer, signed first, followed by the other delegates.
The signing did not itself put the Constitution into operation. Article Seven required ratification by conventions in at least nine states. New Hampshire became the ninth state to ratify on June 21, 1788, and the new federal government began operating in 1789.
September 17 is now observed in the United States as Constitution Day and Citizenship Day. The date is also distinct from July 4, 1776, when the Declaration of Independence was adopted, and from March 4, 1789, when the Constitution replaced the Articles of Confederation.