Butch,
The 9th Ky. Inf., along with the rest of the Orphan Brigade, was converted to mounted infantry in early September 1864, in the area of Barnesville, GA, following the battle of Jonesboro and the end of the Atlanta Campaign.
For some info on the final Orphan Brigade soldier killed (George Doyle, Co. A, 9th Ky. Inf.), see:
http://www.rootsweb.com/~orphanhm/scarcamp.htm
http://www.rootsweb.com/~orphanhm/lastshots.htm
Geoff