Fort Mifflin
Why it's listed
Fort Mifflin occupies Mud Island in the Delaware River at Philadelphia, and its buildings were added in several phases from 1772 onward. The surviving stone river wall, laid in the eighteenth century, was regarded as notable for its masonry and for its role in the siege of October-November 1777. The Commandant's House, a pilastered brick building probably begun in 1794, is attributed to Pierre Charles L'Enfant, who worked at the fort in the early 1790s. The 1814 Officers' Quarters has a double gallery facing the parade ground with cast iron grillwork and turned wooden columns. The artillery shed of about 1837 is described as a rare surviving example of its building type. Its engineers included several French officers who had served with Lafayette or emigrated after the Revolution.
Machine-generated summary. This summary was generated by a language model from the official nomination document and has not been reviewed line by line by an editor. It may contain errors. Check the source document before relying on any detail. Source: nomination document (PDF) · catalog entry. Generated October 2026 (model claude-haiku-5-5, prompt v1.1-2026-10-29).
| Period of significance | 1772-1900 |
|---|---|
| Areas of significance | Military, Engineering |
| Boundary source | NPS cultural-resource GIS polygon |
| Full listing page | Fort Mifflin (property record) |
What listing means for this property
This is a historic district. Buildings within its boundary are either contributing (they add to the district's significance) or non-contributing. Owners of contributing income-producing buildings can claim the 20% federal rehabilitation tax credit; homeowners should look at state credits. National Register districts impose no design review by themselves; a local historic district ordinance, if one exists, does (the difference explained).
General information, not legal or tax advice. Rules change; confirm with your State Historic Preservation Office or a qualified adviser.