Jeff,

Okay,I found your man . A Person A. Davis was a private in Company E of the 14th Texas Cavalry ( Johnsons Mounted Volunteers) . You man shows up on list M227 roll #9. Go to this website:
www.itd.nps.gov/cwss and see if you can find it too. The website will tell you how to get the records, etc. Since the 14th fought in some big battles , you really should not have too much trouble finding information on their activities , at least at the brigade level ( Ector's Brigade) . Glad I could help.
CRaig