As we all know the beginning of the War was to preserve the Union, because once you joined this Union you were stuck and couldn't leave. But I think South Carolina's stance was that if you violate any p[art of the aggreement then the contract is null and void so leaving this Union was proper as they violated the Constitution and refused to obey the Federal laws on a whim.

But the point is, the Union was for safety reasons only. Not for being governed by a Federal Government as we are now.