When the American Revolutionary War broke out in April 1775, the Machias area became one of interest to British authorities in besieged Boston as a source of lumber and supplies. An expedition to the area to acquire materials resulted in the naval Battle of Machias on June 11–12, 1775, in which a small Royal Navy ship was captured by the colonists led by Jeremiah O'Brien, for whom the fort is named. After this event a number of fortifications were erected on the Machias River, including a four-gun battery at this point. This fortification was destroyed when the British returned in force in 1777, sparking a second battle.