The fort consisted of lunettes facing south and west and two bastions to the north to protect it from attack up the ravines from the Potomac. The perimeter was 368 yards with places for 25 guns
The fort was entered from the east by a road that crossed Spout Run and proceeded up the hill to Fort Strong. To provide clear lines of fire for Fort C.F. Smith and adjacent forts, all of the trees for miles around were cut down. Many of the trees were used in construction of the forts and support structures.