While most people are flying into Philadelphia International Airport, they forget to look down. If they did, they would spot this 42-acre Fort That Saved America also known as Fort Mifflin. This was the scene of a horrific six-week engagement that the history books forgot about. Fort Mifflin was one of the three forts in charge of blocking British supply ships form sailing up the Delaware River into British occupied Philadelphia during the Revolutionary War. Joseph Plum Martin wrote in his journal about his hellish experience here during the conflict.