Hi Sue -
here are some possible options for you:
Rains, N.W.B.
Confederate
Cavalry
5th Regiment, Tennessee Cavalry (McKenzie's)
Raines, N.B.
Confederate
Cavalry
19th Regiment, Tennessee Cavalry (Biffle's)
Raines, N.B.
Confederate
Cavalry
5th Regiment, Alabama Cavalry
You need to (1) get the compiled service records (CSRs) for these men or (2) get a good idea if any of these units may have included men from where your ancestor lived (county and state usually good enough).
Good luck!!!
Kenneth Byrd