Michael,

Easy.

Process of elimination. Find out when the picture was made. Look at the type of paper and then look on the back of any markings or photographer. Look at the clothing of both men to give you a clue. See what that sign says. Research all of those guys and find out when they died. Then start looking for elderly pictures of them.

Please let me know if you have any questions.

Respectfully,

Gerald D. Hodge, Jr.
Lieutenant Colonel, U.S. Army (Retired)
M.A. Military History - Civil War Concentration
Research - Preservation
Historian: 39th Georgia Volunteer Infantry Regiment
http://39thgavolinfrgt.homestead.com/39thHomepage.html
Athens, Tennessee