Clear as a cloudy day, perhaps. Yes, slavery was certainly a part of their reason for leaving the Union, but you can't ignore the role that tariffs played either.
In every war there are dozens of underlining causes, but the preservation of the union was the main cause of the Civil War and the main cause of the succession was slavery.
You do know that there was an attempt back during the formation of the country after the revolutionary war to end slavery. The abolutionist movement was alive and well as far back as 1750. HOWEVER, the country just went through a civil war and was in its infancy. It was not ready for an internal conflict, so it settled on a compromise. That compromise was the Northwest Ordinance!
For one to even begin to argue that Fed's abolishing of slavery infringed on the 10th amendment, first does not understand the 10th amendment and 2nd doesn't understand the 5th amendment.
For one to argue that slavery was not a leading cause of the war, doesn't understand the effect the Dred Scott Case had on history or how prevalent the abolutionary movement was in the North (not saying the North didn't have their prejuidices against the Blacks)!
Well the abolitionist movement in the north was not very prevalent, to be honest. As to abolishing slavery being an infringement on the 10th amendment, nobody has made that claim. However, not allowing the states to secede is an infringement of constitutional rights.
Take some law classes before you proclaim yourself a master of the constitution. Otherwise you just look like a fool!