The Massachusetts Charter of 1691 was a charter that formally established the Province of Massachusetts Bay. Issued by the government of William III and Mary II, the corulers of the Kingdom of England, the charter defined the government of the colony, whose lands were drawn from those previously belonging to the Massachusetts Bay Colony, Plymouth Colony, and portions of the Province of New York. The territorial claims embodied in the charter also encompassed all of present-day Maine, New Brunswick, and Nova Scotia.

The Mayflower Compact, originally titled Agreement Between the Settlers of New Plymouth, was the first governing document of Plymouth Colony. It was written by the men aboard the Mayflower, consisting of Separatist Puritans, adventurers, and tradesmen. Although the agreement contained a pledge of loyalty to the King, the Puritans and other Protestant Separatists were dissatisfied with the state of the Church of England, the limited extent of the English Reformation and reluctance of King James I of England to enforce further reform.