Mike
... It appears someone may have just latched onto the first service record found with a matching name and ran with it without cross-checking or digging a little deeper... Actually not that rare to find such mistakes... The subject with the 56th Va is listed as being from Halifax Co Va, but had enlisted in nearby Mecklenburg Co Va... The flat gravestone present is a Govt Vet Admin type/design that didnt come around until much later.

If your ancestor actually served, the only record I found even close was a James A Brooks listed as residing at that time in Maury Co Tenn. Enlisted on Aug 1st 1861 at Cumberland Gap into the 29th Tenn Infantry Regt. Co.C. Listed as deserting on Nov 30th 1864 at Nashville Tenn. Took the Oath of Allegiance on Feb 3rd 1865.

Frederick