Fort Mifflin: The Siege of 1777

Fort Mifflin, originally called Fort Island Battery and also known as Mud Island Fort, was commissioned in 1771 and sits on Mud Island (or Deep Water Island) on the Delaware River below Philadelphia, Pennsylvania near Philadelphia International Airport. It was site of the Siege of Fort Mifflin or Siege of Mud Island Fort from September 26 to November 16, 1777.

Fort Mifflin and Fort Mercer

• Fort Mifflin and Fort Mercer were two American forts on Mud Island near Philadelphia. It was the largest of three forts in the area.
• On October 23, Howe and his brother Richard sent a combined naval and land force to attack the fort.  However, two of the main British ships got stuck, and American fire ships set another one on fire. Two British ships exploded.
• The land attack did not go better.  A force of Hessians attacked Fort Mercer, but the Americans put up a good fight.  They lost 150 men to only 30 Americans.
• On November 11, the British battered Fort Mifflin into submission and the Americans evacuated Fort Mercer.
• Despite all these British victories, Howe was unable to capture Washington’s army.  He returned to winter in Philadelphia, where he had about 37,000 mouths to feed. He had to send foraging parties into the nearby countryside nearly every other day.
• In Philadelphia, Howe lived a lavish lifestyle.  One officer wrote “Howe did not take Philadelphia; Philadelphia took Howe.”