South Carolina, along with much of the Confederacy, seceded mainly because the policy of the Lincoln administration was to prevent the expansion of slavery into the territories. Since the South's economy could not grow without the expansion of the slavery, it drove them to secede. The states seceded almost exactly in order of how much of their population was comprised of slaves. The "federalism" excuse was just that...an excuse.
South Carolina did not succeed from the union because they wanted it to be a "slave union". South Carolina succeeded because its people viewed that the federal government was taking too much control of their state (which is obviously under control of the state's governing body). Orignally the United States was set up to be more like a confederacy that a union, but the civil war changed all of that.
The first Souther state to leave was South Carolina, because the north wanted it to be a free union and the south wanted it to be a slave union.
And the North had all the industrys and paid crap to the south to make cotten. The North was rich of the south.
It was South Carolina on December 20, 1860
my guess is south carlina