These giant mortars, in these positions, were part of Union Gen. George McClellan’s siege of the Confederate defense line along the Warwick River.

These 13-inch (bore diameter) guns lofted heavy explosive shells (balls at right) onto the vicinity of the Rebel positions, frightening the defenders and causing casualties which Gen. Joseph E. Johnston’s smaller forces could not afford.

McClellan, ever overcautious, was convinced that he faced an overwhelming Confederate army and it took weeks for President Lincoln to budge him.