Hi Melvin: An (in-law) ancestor of mine was a slave, who was recruited by the 1st Connecticut Cavalry, in Fairfax County, Virginia in 1862 and was hired as a scout/ blacksmith and performed his duties until the surrender at Appomatox Court House, where the returns place the 1st Conn. Cav. on Apri 9,1865.
I have tried to find some record of him at the U.S. Archives, but no luck so far. I did find my great Uncle's file, who was a Buffalo Soldier and contained his home town, his mother's name and his future wife's name and when he retired. You may want to try the U.S. Archives for Jack Bass. I do not know if any civilians who worked as cooks, teamsters, nurses, spies, scouts, etc. were considered as regular members of the service.