Maggies,
It would be beneficial to know the name of your ancestor.
Capt. Walter O. Woods commanded Co. B, 14th Kentucky Infantry, U.S. Volunteers. Over 100 men served in Co. B. Knowing your G-Grandfather's name would help determine if a photo exists and also detail his service. In the meantime check this.

http://freepages.military.rootsweb.com/~us14thkyinfantry/photo/main.html

Len