Like I've said in this thread - I really don't care for what the Civil War did to the power of the Federal government. It began a process that I find little agreement with, to include Congress' delegation of its responsibility to the executive - not only in declarations of war, but in the entire corpus of federal regulation.
But be that as it may, the war began because the South insisted on being allowed to extend slavery as they saw fit.
There were no other first-order causes.
You are truly myopic in believe that slavery was the only cause, and wholly brainwashed.