University City Historical Society

Fort Mifflin

Marina Road and Penrose Ferry Road

Placed on the National Register of Historic Places September 26, 1999

The fortifications and the group of buildings at Fort Mifflin have a long history, with building activity corresponding chronologically with many of the major phases of the nation's past. The building phases, roughly, were (1) 1772&1775; (2) 1779&1781; (3) 1794&1798; (4) 1814& ; (5) 1835&1839; (6) the 1870's and (7) various repairs and innovations in the twentieth century.

Fort Mifflin in 1930
Fort Mifflin in 1930(?)

Many of the existing structures within the fort walls, aside from the associations with historical events and dramatic conflicts, are interesting and important in their own right, architecturally. The commandant's home, an elegant pavilion-type mass of pilastered brick, was built in the third phase (1794, probably), possibly over the foundations of the original house, and was constructed most probably by L'Enfant, active at Fort Mifflin in the early 1790's. The 1814 officers quarters present a double-galleried facade to the parade ground, with excellent grille work and turned wooden columns. Possibly the only survival of its type, the early nineteenth century artillery shed is remarkably well-preserved and educational as a rare example special building types. And from structure to structure, there are points of interest and value in each, with each representing a separate architectural and historical style and period, the ensemble, however, presenting to the eye a surprisingly handsome and homogeneous whole.

Of special significance, because of the excellence of its eighteenth century stone masonry and especially in light of its role in the famous siege of October–November, 1777, is the old wall on the river front. These four redans put up on land purchased from Joseph Galloway, were part of the first (1772–1775) or "Montresor" phase of the building program and survived the devastating bombardment to appear on all the late eighteenth-century maps and drawings and to receive mention in contemporary journals, letters and reports. Hence the "wall of Masonry" "ten feet high "mentioned by Major deFleury during the November, 1777 conflict was joined to the new works, begun 1780 when the Pennsylvania Executive Council ordered Major William Armstrong to …finish the parapet so as to enclose the whole and form a compleat Redoubt… This work of extension was noted by the Marquis de Chantellux in his 1780–82 journal. A more comprehensive scheme was proposed 19 April 1794, by L'Enfant: …I would establish the forts and batteries back of the wall now standing, masking this serve as a cover until the work is sufficiently advanced… In a report of 25 September of the same year, L'Enfant states that the … next work is the old wall rampart of about 290 yards long, of that wall, the remains of the old fort, 160 yards has been banked inside, ready to form a parapet and rampart platforms; the whole about 45 feet broad and on an average of ten feet high … L'Enfant's ambitious schemes were apparently altered before 1797 when Louis Tousard was requested to finish the fort on a plan projected by Lieutenant Colonel Rochefontaine, which work was described by a traveler (the naturalist R. J. de Costa) as consisting of … three batteries set on stone walls two arms lengths in height. In a very important and comprehensive report of 1802, previously unnoticed until the current research program, Colonel Jonathan Williams noted that the first part (of the fort; that built by the British and finished since by us), is formed of four redans defending the river on the south and east. The walls generally eleven and a quarter feet high are of large stones perfectly cut and put together; in fact they require no repair whatever… In another (1807) report Williams locates the exact place where the old stonework ended and the brickwork began; and the break exists today in the same location. (See Frank Barnes' 1956 study of this document and others, which proves beyond doubt the authenticity of the existing stone wall). This old wall was pointed and raised two feet in height, to make it uniform with the other parts of the work… in 1836. Another layer of masonry was constructed towards the middle of the 19th century.

Fort Mifflin in 1929
Fort Mifflin in 1929(?)

Of interest to students of the art of fortifications engineering is the long list of distinguished engineers attached to the works at Fort Mifflin, beginning with Captain John Montresor, the Chief Engineer of the Crown, and including many able Frenchmen such as Rochefontaine, Dupontail, DeFluery, Auguste le Brun, Villefranche, who had accompanied Lafayette or had emigrated to this country following the French Revolution.

And to the most extensive part of the existing building scheme is attached the most famous of these names, that of Pierre Charles L'Enfant.

Description of Buildings

This description of Fort Mifflin applies primarily to the structures within the fort rather than the wall itself. The wall as described in the significance statement had been bombed, added to, rebuilt, and repainted throughout the years.

Blacksmith's Shop
before 1802

A 18' x 23' one-story building constructed of brick masonry with a gabled roof of wood rafters and cedar shackes and having two forge chimneys and one forge base. The building has a brick floor and interior finishes of wooden doors, windows, woodwork and wall stripping with cast iron pegs located on the north and south walls, circa 1836.

Soldiers' Barracks
before 1802; probably 1794–95; interior work 1836 (possibly constructed in the 1779–81 building phase)

A 28' x 117' building, one-story, with an attic story, dormered, a gabled roof and colonnaded gallery toward the parade ground. The construction is brick masonry, plastered with interior finishes of wooden doors, windows, and woodwork are, circa 1836. The building is roofed in tin.

Officers' Quarters
1814; interior work in 1836

A 28' x 80' two-story gable-roofed brick masonry building with colonnaded galleries having elegant cast iron grille work and turned wood columns facing the parade grounds. The gallery floor supports are uniquely of cast iron and the interior finishes of doors, windows, and woodwork are circa 1836.

Commandant's House
1794–1795; 1836; and possibly earlier than first phase mentioned: 1772–75 foundation structure?

The Commandant's house is a story-and-a-half brick structure, 35' x 70' with brick pilasters, a parapet, and low hipped roof. There is an off-center corridor along the northwest-southeast axis, with two rooms to the right of the main entrance with fireplaces back-to-back; to the left of the corridor are four rooms, all serviced by one central chimney stack. Woodwork and marble mantelpieces, circa 1836. The low upper rooms are only partially finished and lit by small windows at the parapet range. There is a strong possibility that this structure, built during the 1794–95 (or L'Enfant) phase, is built over the foundation structure of the first (1772–74) building phase.

Artillery Shed
approx. 1837

As stated in the Barnes report of 1966, one of the best examples of a special building types of that period still remaining.

The building is 37' x 97', having a gabled roof of wood rafters and cedar shakes, and is brick masonry structure with a single interior colonnade of one-piece square stone columns in front of which has been added a frame frontal shed roofed addition. The interior consists of a free standing wood artillery storage platform about 20' x 90' having excellent woodwork, circa 1837.

Main Entrance

Massive entrance doors and arch on northeast river side. The gate flanked by massive stone quoining and brick jamb supports. The arch has a head stone dedicated, to President Adams. The doors are heavy wood planks with cast iron straps, bolts, hinges and lock arm of the Civil War period.


A gabled roof, brick masonry (pointed) 20' x 56' st6ucture with windows, doors, and woodwork, circa 1843.


Originally a guard house, this gabled slate-roofed, 24' x 44' brick masonry building has a partial barrel-vaulted interior and unique, round, barred windows with interior sliding wood sash.

before 1802 (1790's?)

Constructed prior to 1802, this building, known on drawings and reports as the "mess building", is a 40' x 110' 2-story structure and has a gabled roof with galleries on the east elevation and is constructed of brick masonry. It has the original window glass and double hung sash under the galleries on both floors still remaining.

Main Magazines

Vaulted interiors of excellent brickwork with bermed earth covering.

Size of main room: approximately 15' x 43'.

Torpgioo Casement

Vaulted interiors of excellent brickwork with bermed earth covering.

Size of main room: approximately 11' x 17'.

Principal Sources

At the National Archives Record Groups 77 (Records of the Office of the Chief of Engineers), and 92 (Records of the Office of the Quartermaster General), the Buell Collection of historical documents relating to the Corps of Engineers 1801–1819, NA microfilm publication #661: "Historical Information Relating to Military Posts and other installations, circa 1700–1900," The War Department Collection of Revolutionary War Records, NA microfilm publication from Record Group 11: "Papers of the Continental Congress, 1774–1789;" the published Archives of Pennsylvania; the Pennsylvania Magazine of History and Biography; the Samuel Smith Papers at the Butler Library, Columbia, The Digges-L'Enfant-Morgan Papers at the Library of Congress; the Louis Tousard letterbook at Eleutherian Mills Library; the journals and notebooks of Captain John Montresor; the de Fleury material in the Sparks Papers at Cornell; The American State Papers: "Military Affairs"; and the cartographic, prints, drawings, and other special collections divisions at the National Archives, The Library of Congress, and the Historical Society of Pennsylvania.

This National Register Nomination was prepared by R. Michael Schneider of the Historic American Builders Survey.

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