Fort Mifflin on the Delaware

Fort Mifflin on the Delaware is a National Historic Landmark on Mud Island in the Delaware River near Philadelphia, established in 1775 and best known for withstanding what many historians consider the greatest bombardment of the American Revolution, a six-day siege in November 1777 that helped Washington's army reach Valley Forge safely. The fort later served through the Civil War and both World Wars before its decommissioning, and a nonprofit has stewarded the grounds as a landmark since 1986, maintaining the fort's 1777-1875 appearance. Today the fort hosts weddings, corporate events, charity fundraisers, and social gatherings across a mix of indoor and outdoor spaces. Its bombproof Casemates can be turned into a wine cellar or speakeasy-style setting, while the Hospital Building, Bunk Room, and a riverfront picnic area with working fireplaces serve as options for meetings and private functions. Special-event bookings can include cannon demonstrations, interpretive guides in period attire, weapons displays, and ghost tours for a distinctly historic atmosphere.