Fortifications, Manassas, Occupied by 13th Mass., 1862, Albumen silver print from glass negative, Image: 7 5/16 ? 9 1/4 in. (18.6 ? 23.5 cm), Photographs, Mathew B. Brady (American, born Ireland, 1823??1896 New York), In summer 1861 Mathew B. Brady b