During the Revolutionary War, Washington Square served as a mass grave, and today it is a park. Washington Square was one of William Penn's original five squares, used first as common land and then as a burial ground. During the winter and spring of 1777 to 1778, while the British occupied Philadelphia and Washington's army endured the winter at Valley Forge twenty miles away, thousands of American soldiers and British prisoners died in the city of disease, wounds, and cold, and were buried in mass graves in this square.
Estimates suggest that more than two thousand soldiers are interred here. After the war, the square became a park, then a publishing and bookselling district in the nineteenth century — the American book trade was centered around Washington Square for decades, and Lippincott's, America's oldest continuously operating publisher, had its offices here. The Tomb of the Unknown Soldier of the American Revolution was dedicated in the center of the square in 1957, with an eternal flame burning beside a bronze statue of Washington.
Beneath the tomb are the remains of an unknown soldier exhumed from the burial ground. Look at the flame burning beside Washington's statue; it marks the dead of the first American war.