when was the constitution ratified

The U.S. Constitution was ratified on June 21, 1788, when New Hampshire became the ninth state to approve it, which met the requirement for ratification by nine of the thirteen states and officially made the Constitution the framework of the United States government. The Constitution had been signed earlier on September 17, 1787, and then sent to the states for ratification. Delaware was the first state to ratify it on December 7, 1787. The ratification process concluded with Rhode Island being the last state to ratify on May 29, 1790.