Any power not reserved for the federal government is the right of the state. The Founding Fathers did not want a state trapped in the country, if the federal government turned against the state. The right to secession was a final check on the Federal government if it turned against a state.
There may be an arguement that states seceded over slavery, but the federal government did not wage war over slavery. It waged war to bring those states back into the union so they can continue to supply the textile barons with bottom-priced cotton.
My argument has long been this: If they have a *RIGHT* to secede, then their reasons for doing so do not matter.
A right isn't a right if you are only allowed to exercise it for approved reasons.
And yes, the South was a money stream for the powerful industrialists in the North who had evolved control over the government.
The War was about that money, and they didn't really care about the slaves.