From 3Fold, a subscription site with many military records, I found this information:
James Greathouse, Pvt, 1st VA Rangers, Roll of Prisoners at Camp Chase, Ohio, transferred to Cairo, IL, Nov. 20, 1862, for exchange by order of Col. Wm Hoffman, D.G. of Prisoners, in charge of Lieut. Wm G. Neilson, C. D. Govs Guards.
Captured Roane Co VA, Nov 3, 1862; Age 51, 5’9”, eyes blue, hair dark, complexion, dark. Received Nov. 13,1862, from Wheeling, VA.
That was all I found for him.I found brief records for Wm Greathouse, Samuel Greathouse, and Jesse Greathouse, all enlisted in Calhoun Co. VA (now W. VA), which borders Roane Co.Do you know his son’s name?Do you know anything further about Nancy Ashley Greathouse.Where was she after the war?