[Yorktown, Va., vicinity. Topographical engineers, Camp...

Photo shows a group of nine men posed in front of a tent with a surveying instrument at left. The two men seated center and right are most likely Frederick W. Door and John W. Donn. The officer seated to the left is William H. Paine who invented the steel tape reel worn by the man standing on the right. Standing second from right appears to be Allan Pinkerton. (Source: U.S. Corps of Topographical Engineers, 2011, ). Photograph from the main eastern theater of war, the Peninsular Campaign, May-August 1862.