Who was the principal author of the Massachusetts Constitution of 1780?

John Adams was the principal author of the Massachusetts Constitution of 1780.

The Massachusetts Constitutional Convention appointed a committee that included James Bowdoin, Samuel Adams, and John Adams to prepare a constitution. The committee delegated the drafting work to John Adams, who produced the document’s main structure and language. Voters approved it on June 15, 1780, and it became effective on October 25.

The constitution established a framework with a declaration of rights, a bicameral legislature, an executive, and courts. Its design influenced the United States Constitution, which was drafted seven years later. Adams’s work also reflected the revolutionary-era effort to replace colonial government with written republican institutions.

Massachusetts’s document is notable for remaining in continuous effect, with amendments, since 1780. It is among the oldest functioning written constitutions in the world. The state constitution should not be confused with the U.S. Constitution, whose principal drafting convention met in Philadelphia in 1787 and whose principal architect is often identified as James Madison.