The Massachusetts Constitutional Convention of 1853 met in order to consider changes to the Massachusetts Constitution. This was the third such convention in Massachusetts history held by delegates selected for the purpose: the first, in 1779–80, had drawn up the original document, while the second, in 1820–21, submitted a number of articles to a popular vote, resulting in the adoption of the first nine amendments and the rejection of a number of other proposals. Since 1853, Massachusetts has had one subsequent constitutional convention, in 1917–18.
George S. Boutwell was inaugurated Governor in January 1851. This "marked the beginning of a determined drive for the elimination of the 'inequalities' in the system of representation." A joint committee on representation of the Massachusetts General Court recommended an amendment giving smaller towns an unfair advantage over the larger ones, and it failed to reach the required two-thirds majority in the House. However, the drive for reform persisted, and a Senate bill provided that the people be asked whether they wished for a constitutional convention. The bill passed, but on November 10, 1851 the idea of a convention was rejected by a vote of 65,846 against to 60,972 in favor.
Undeterred, the Legislature on May 7, 1852 passed "An Act relating to the calling a Convention of Delegates of the People, for the purpose of revising the Constitution". On November 8 of that year, the following question was answered in the affirmative by the voters:
Is it expedient that delegates should be chosen to meet in convention for the purpose of revising or altering the Constitution of government of this Commonwealth?
Delegates to the Convention were elected on March 7, 1853, with each town entitled to the same number of delegates as it had representatives in the Massachusetts House of Representatives.
The Constitutional Convention met at noon on Wednesday, May 4, 1853, at the State House in Boston. There were around 420 delegates, though often substantially fewer were actually present for votes. For instance, on a vote taken in the session of July 28, regarding Proposition Number Five, only 165 members–less than half the full body–were present and voting.