Born in Massachusetts, John Winslow joined the British army in around 1740 as a Captain in Richard Philipps' Infantry Regiment in Annapolis Royal. In 1754, appointed Major General of the militia by Massachusetts Governor, William Shirley, he saw to the construction of the Forts Western and Halifax in today's Augusta and Winslow regions of Maine. Promoted to Lieutenant-Colonel, he participated in the expedition against the Fort Beauséjour in the Isthmus of Chignectou, in June 1755. During the Deportation, he was in charge of expelling the Acadians from the Minas Basin (Grand-Pré region) and was somewhat sympathetic to their fate, describing his duties as "very disagreeable to his nature and character". In November 1755, he returned to Massachusetts after having contributed to the expulsion of over 1,500 Acadians. He died in Hingham, in April 1774.