Commandant's House - 1835
Report from the War Office16 January 1796 · Timothy Pickering, Secretary of War
A fort, on Mud Island, is about half done, and a Citadel has been erected to complete the fort ?
Report from the Fort21 January 1802 · Major J. J. Ulrich Rivardi
The Citadel of brick, one story high 70 feet by 34 contains one room 27 by 27 - two rooms 20 by 15, two smaller ones, one kitchen and a porch. The garret is surrounded by a gallery and a breastwork of brick, but no defense could be expected from that building, as an enemy can stand all round close to the wall without the least injury. That building has settled considerably and the walls round the chimneys are in some places one inch open.
The brick structure built in the center of the parade ground as a Citadel was completed by 1796 in conjunction with Pierre Charles L'Enfant's plan for redesigning Fort Mifflin. Defense of the port of Philadelphia was particularly critical at the time, for the city served as the capital of the new nation. In military terms, a citadel meant a place of last retreat. In 1794 most seacoast fortifications along the Atlantic were required to include citadels built over ammunition magazines. No mention of such a magazine has been associated with Fort Mifflin's Citadel. Architectural investigation has shown, however, that forty-five gun portals were originally built at regular intervals in the two-foot thick walls. By standing on a platform, a soldier could have shot a musket through these openings. Additionally, a brick parapet ["breastwork of brick"] extending seven feet above the roof line hid a lookout platform ["gallery"] around the perimeter of the roof. A massive timber-frame truss system spanning the thirty-foot width of the building and two symmetrically placed chimneys provided flexibility of interior space. A central flagpole went through the roof and was used as a signal system to the city. The building had defensive characteristics, but Rivardi's comment implies they were not particularly successful.
The rooms described in Rivardi's report and evidence from the building show it could also have been used as a residence, probably for an officer. The architectural symmetry and fine detailing of the initial 18th-century building - cut stone foundation, ornate brickwork, pilasters with wooden capitals, and a brick porch - imply the Citadel was created with a flare for design and style fit for the commander of a military post. In 1815 the building was referred to as the Commandant's House, and by then all the gun portals except those on the porch had been closed with brick.
In 1802 Rivardi complained that the Citadel had structural problems, and such reports continued until the entire fort was rehabilitated in 1835. By that time the roof - with its gallery, flagpole, and weak chimneys - was sacrificed to change the building from a defensive Citadel to a residence for two commanding officers and their staff. Radical changes were made in the structure. The roof was raised to the top of the parapet, creating a second-floor living space where only a garret or attic had existed. The flagpole was left in place but was cut down to a stub that protruded from the top of an added, octagonal, windowed copula. The north chimney was moved from its symmetrical location and the south chimney was altered to achieve added fireplaces for more rooms. The foundation was reinforced with concrete and cement, and new joists and flooring were laid. All new interior walls, windows, doors, and woodwork were added, and end doors and windows were closed to make closets and walls. The porch was enclosed to create two vestibules. On the outside the entire building was stuccoed to hide all the changes.
The result was commanding officers' headquarters with rooms for two officers consisting of bedrooms and kitchens at the south end, a central hallway, and two offices at the north end. Separate vestibule entrances on the former porch led to each living area. The second floor space served for servants or storage.
No record has ever been found showing that two officers shared this residence. After the Civil War, when the fort was rehabilitated, and innovative coal-burning stove was installed in one kitchen, and the building became a family residence. Plumbing was never installed in the building, but privies existed in the southwest corner of what became a backyard on the west side of the house. By the 20th century minimal electricity was added.