Humiston was a member of Company C, 154th New York Infantry. During the fighting on the first day of the Battle of Gettysburg, he was killed and buried among the unidentified dead. There was little on his body that could establish who he was. The photograph he carried, however, offered a clue. It showed three young children, but no name was attached to it.
Dr. John Francis Bourns, a Philadelphia physician who had worked among the wounded at Gettysburg, became determined to identify the unknown soldier. Descriptions of the children's photograph were published in newspapers, and copies of the image were distributed in the hope that someone would recognize them.
The search eventually reached Portville, New York, where Philinda Humiston recognized the children as her own. They were Franklin, Alice, and Frederick Humiston. The unknown soldier was finally identified as her husband, Amos.
The photograph then took on a life of its own. Copies were sold to raise money for Humiston's widow and three children, and later became part of efforts to support children who had lost fathers during the war. The image became known as the “Children of the Battlefield.”