Built in 1771, Fort Mifflin has served in multiple wars—and some say, still does. Its restless dead include Elizabeth Pratt, the “Screaming Woman,” mourning her children lost to yellow fever; Joseph Adkins, the lamplighter seen carrying a glowing oil lamp; and Jacob the Blacksmith, hammering at his forge long after death. Visitors also report a faceless prisoner sewing in Casemate 5 and even a ghostly tour guide in full Revolutionary attire who answers questions before vanishing. Additionally, visitors and rangers report cannon blasts, phantom footsteps, and lanterns lighting on their own near the old barracks. Featured on Ghost Hunters and countless YouTube investigations, it remains one of the oldest verified hauntings in the United States.