The Constitutional Convention convened May 14, 1787, in Philadelphia, and concluded its work on September 17, 1787, when it transmitted its recommended new Constitution to the states for ratification, which occured June 21, 1788, when New Hampshire ratified, the ninth state. The remaining states ratified shortly thereafter.
Every year we celebrate Constitution Day on or about September 17, which is also mandated for all schools receiving federal funds. Not all schools are yet doing this as well as they should, so this site exists to encourage better participation. It is intended to serve as a clearing house for celebrations of the Constitution of all kinds.