National Massachusetts Day is observed every August 17 as part of the National State Days project initiated by National Day Calendar in 2017. This holiday celebrates Massachusetts, the sixth state to ratify the U.S. Constitution, and recognizes its rich history, including its role in the American Revolution and the establishment of the first permanent English colony, Plymouth Colony, in 1620. The state, named after the Indigenous Massachusett people, is noted for its significant events such as the Boston Massacre and the Boston Tea Party. Massachusetts, the most populous state in New England, was officially established as the Province of Massachusetts Bay in 1691, merging several British colonies. Celebrations may include educational activities highlighting the state's contributions to American history and culture.