"SLAVERY OR STATES RIGHTS

The secession epic's twist and turns mock Civil War buffs' debate about whether slavery or states rights caused the disunion. The story is incomprehensible without both contributory causes. Assuredly, Lincoln's supposed menace to salvery impelled the first seceders. Equally assuredly, the Union's actual menace to a state's supposedly exclusive right to withdraw consent helped spread the movement beyound the initial preciitators." William W Freehling, Senior Fellow at the Virginia Foundation for the Humanities.
From his "The Road to Disunion:Secessionist Triumphant, 1854-1861. Oxford University Press, March 2007