He was found dead on the battlefield at Gettysburg, an unknown soldier with nothing to identify him but an ambrotype of his three children, clutched in his fingers. With the photograph as the single, sad clue to his identity, a publicity campaign to locate his family swept the North. Within a month, the bereaved widow and children were located in Portville, New York, and the devoted father was revealed to be Sergeant Amos Humiston of the 154th...