Philadelphia, PA, United States
Fort Mifflin. Laid out in 1771 by the engineer John Montresor. Heroically held by the Americans under British siege until they were forced out, Nov. 15, 1777. Rebuilt 1798-1800 according to L'Enfant's design and enlarged in the 19th century. A U.S. military post until the 1950s.
Listen to the audio guide for Blue plaque № 29465 Free on WIP — starts by itself when you arrive, even with the screen off