The house was built by Edmund Fowle (1747–1821) in 1772, and was originally located on Mount Auburn St., then called Mill St. Watertown was the seat of Massachusetts Provincial Congress, its "de facto" government, during the British occupation of Boston in the American Revolution. The committees of the 2nd and 3rd Provincial Congress met in this house from April 22 to July 19, 1775, and the Executive Committee met here from July 19, 1775, to September 18, 1776. In 1776 the Treaty of Watertown, the first treaty signed between the newly formed United States of America and a foreign power, the St. John's and Mi'kmaq First Nations of Nova Scotia, was signed in this house.