Fort Mifflin (Philadelphia, Pennsylvania)
Philadelphia · Pennsylvania · Revolutionary War
History & Significance
Fort Island Battery, commissioned in 1771 on Mud Island in the Delaware River, was also known as Mud Island Fort. Following the Declaration of Independence, Benjamin Franklin chaired a committee to defend revolutionary Philadelphia, and the Committee of Public Safety completed fort construction in 1776.
Fort Mercer was simultaneously constructed in New Jersey, with the two forts intended to restrict Royal Navy operations on the Delaware through chevaux de frise obstacles—wooden-framed structures spanning the river's width. The siege from September 26 to November 16, 1777, involved British land batteries and a naval squadron attempting to capture the fort; Lieutenant Colonel Samuel Smith commanded initially until wounded, and his successor, Major Simeon Thayer, evacuated the garrison on November 15.
The fort experienced the heaviest bombardment of the Revolutionary War, leaving 250 of 406 to 450 men killed or wounded. Renamed in 1795 for Thomas Mifflin, a Continental Army officer and Pennsylvania's first post-independence governor, the fort was rebuilt by the U.S. Army beginning in 1794 and garrisoned into the nineteenth century. Fort Mifflin housed prisoners during the Civil War and was decommissioned for active duty infantry and artillery in 1962.
Key Facts
Map
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🧳 Visiting
What you’ll see when you visit:
- Revolutionary War bombardment site with surviving masonry walls and gun batteries
- Delaware River island setting with views of Philadelphia and shipping traffic
- Museum exhibits on the 1777 siege and American military history
- Restored barracks, officer quarters, and period military structures
- Active U.S. Army Corps of Engineers facility alongside historic preservation
Sources
- https://en.wikipedia.org/wiki/Fort_Mifflin
- https://www.battlefields.org/learn/revolutionary-war/battles/siege-fort-mifflin
- https://www.fortmifflin.us/the-history/
- https://www.ushistory.org/march/phila/mifflin.htm
- https://pabook.libraries.psu.edu/literary-cultural-heritage-map-pa/feature-articles/mifflin-fort-saved-america
- https://explorepahistory.com/hmarker.php%3FmarkerId=1-A-D8.html
- https://en.wikipedia.org/wiki/Siege_of_Fort_Mifflin
- https://www.battlefields.org/visit/battlefields/fort-mifflin
Other Forts in Pennsylvania
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