At some point you need to read the Confederate Constitution and compare it to the US Constitution. (I was fortunate enough to see the original)
http://www.yale.edu/lawweb/avalon/csa/csa.htm
Also look here for interesting documents:
http://www.yale.edu/lawweb/avalon/csa/csapage.htm
Turtledove's novels have been mentioned. For a straight up historical novel that is quite good, Fort Pillow deals with that battle and Gen. Forrest.
Don't forget to read up on the western theater - often overlooked.