If the issue was more complex than just slavery, why did every state mention slavery explicit in their articles of secession?  I'm sure that there were other things that bothered them, but all of the states included slavery as a reason to leave.  I do mean that as an honest question, since even growing up in PA, they tried to sell the idea that slavery wasn't an important part of why the civil war was fought.

https://en.wikipedia.org/wiki/Declaration_of_the_Immediate_Causes_Which_Induce_and_Justify_the_Secession_of_South_Carolina_from_the_Federal_Union