On what date was the United States Constitution signed at the convention that shaped America250 history?

The United States Constitution was signed on September 17, 1787, at the Constitutional Convention that shaped America250 history.

The signing took place at the Pennsylvania State House, now called Independence Hall, in Philadelphia. The convention had met for four months to replace the Articles of Confederation with a stronger federal framework. George Washington, who presided over the convention, signed first, followed by delegates from the participating states.

Thirty-nine delegates signed the final document, representing 12 states. Rhode Island had declined to send delegates, and some convention participants, including Edmund Randolph and George Mason of Virginia, did not sign. The document still required ratification by the states before it could take effect.

The Constitution became operative after New Hampshire became the ninth state to ratify it on June 21, 1788. The new federal government began under the Constitution on March 4, 1789, making the signing date an important milestone but not the date the government began.