There are always winners and losers in every election.
The South had more then its fair share of representation in the Federal government (2/3 rule counting slaves).
So what was their beef?
"So what was their beef?"
What was the beef in them leaving if they had such control then?
The South wanted out. If you're going to ask me what specific cause each person wanted out FOR I couldn't say. Aside from freedom from the Fed, I have no answer. And I'm afraid noone can have an answer to it.