The image below shows a capstone from a wall which surrounded the old Armory grounds in the early 19th century. This capstone, located in the ground outside the southwest exterior door of the School house, is made of sandstone, which was typically obtained from quarries in Seneca, Maryland.
This stone weighs approximately 500 pounds. In view of its weight, the labor it would take to move it up to the School house yard, and the likely use of the Church and School house as make-shift hospitals in the Civil War, some Harpers Ferry residents speculated that this stone might cap and memorialize a burial of amputated limb bones. We were careful in moving the stone so we could excavate beneath it, and we were ready to contact the State Historic Preservation Officer of West Virginia in the event we uncovered any human remains, so we could obtain guidance on how best to proceed. (In 2018, an excavation sponsored by the National Park Service in Manassas, Virginia, uncovered such a burial of amputated limb bones (link)).