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 remains the oldest functioning written constitution in continuous effect in the world. It was also the first constitution anywhere to be created by a convention called for that purpose rather than by a legislative body. Only the Constitution of San Marino has sections still in force that are older.