3. Fort Mifflin, Pennsylvania
Perched on Mud Island along the Delaware River, Fort Mifflin was constructed by the Continental Army to defend Philadelphia from British forces. Its earthwork design, unlike the imposing stone fortresses of the era, absorbed enemy fire and prolonged the city’s resistance during a critical stage of the Revolutionary War. Though often overshadowed by grander structures, Fort Mifflin’s resilience and ingenuity are celebrated through ongoing restoration efforts. Today, visitors can explore its storied grounds and experience a living piece of American military history.
