I recall that someone posted here a time or two the idea that the Confederate States seceded over the issue of "states rights" - as a citizen of the original seceding state, South Carolina, I have disagreed with that and for anyone who cares to read it, here is one of the historical documents that show the Confederate States were actually invoking their constitutional rights as slave holding states, rights identified by Congress and set forth in the US Constitution. It is clear from reading the entire document that the issue, the only issue was the right to practice slavery. Pure and simple.
The document is called: Declaration of the Immediate Causes Which Induce and Justify the Secession of South Carolina from the Federal Union. http://avalon.law.yale.edu/19th_century/csa_scarsec.asp
