From 1775 to 1777 he served as president of the Massachusetts Provincial Congress' executive council, the "de facto" head of the Massachusetts government. He was elected president of the constitutional convention that drafted the state's constitution in 1779, and ran unsuccessfully for governor in 1780, losing to John Hancock. In 1785, following Hancock's resignation, he was elected governor. Due to the large debts of Massachusetts, incurred from the Revolutionary War, Bowdoin ran on a platform of fiscal responsibility. During his two years in office the combination of poor economic conditions and his harsh fiscal policy laid down by his government led to the uprising known as Shays' Rebellion. Bowdoin personally funded militia forces that were instrumental in putting down the uprising. His high-handed treatment of the rebels may have contributed to his loss of the 1787 election, in which the populist Hancock was returned to office.