The Constitution of the Commonwealth of Massachusetts is the fundamental governing document of the Commonwealth of Massachusetts, one of the 50 individual state governments that make up the United States of America. As a member of the Massachusetts Constitutional Convention of 1779, John Adams was the document's principal author. Voters approved the document on June 15, 1780. It became effective on October 25, 1780, and is among the oldest functioning written constitutions in continuous effect in the world. (The constitutions of San Marino and Vermont have sections still in force that are older.) It was also the first constitution anywhere to be created by a convention called for that purpose rather than by a legislative body.