Fort St. Fr?d?ric consisted of an outer, bastioned stone wall enclosing the Citadel, a four-story, eight-sided tower with walls twelve feet thick at the base. Cannon were mounted on each floor of the Citadel, and entry was gained by a drawbridge over a dry ditch. This fortress-within-a-fort contained living quarters for officers and men, a bakery, armory, and storerooms. Swivel cannon were mounted around the perimeter of the fort's walls.
British expeditions led by General William Johnson (1755) and General James Abercrombie (1758) attempted to capture Fort St. Fr?d?ric without success. Finally, in 1759, the French garrison partially demolished the fort before retreating in the face of an overwhelming force of British and provincial troops under the command of General Jeffrey Amherst.