Regardless of individual reasons for taking up arms, what was the officially stated cause for secession? I can quote the declarations if you'd like.
I've addressed this argument at least 100 times on this forum. I think I addressed it earlier in this thread. The state official declarations of secession prominently mention slavery because slavery was the issue. It wasn't the principle. That is VERY important. We have to remember that slavery had not been outlawed, it wasn't illegal to own slaves, and the US's own Supreme Court had repeatedly defended the right to own slaves as property. So you are literally arguing the South declared secession over something that did not yet exist.
Yes, slavery was the prominent issue at hand, but it was NOT the principle on which secession resided. That was Federalism! Whether the US Federal government had authority under the Constitution to take the property (or in this case, render it worthless) of state citizens. MANY people (then and now) believe such issues are a STATE matter and the Constitution clearly states it as such.
Congress had 89 years and countless opportunities to condemn slavery and outlaw it. The SCOTUS also had ample opportunities to condemn slavery and render it unconstitutional. These things did not happen in America. That's NOT the fault of the South or Southerners. Are they complicit? Do they share a part of the burden? Of course! But to attempt to revise history so as to lay the entire blame at their feet is deplorable and dishonest. Furthermore, I believe it is done in order to scapegoat the South and absolve the North from any and all culpability. This is bigotry at it's finest.
The "reason" was not slavery! The "reason" for secession was in order to form a new nation. A Confederation of states who determined their own parameters and laws as opposed to a Union of states with a central Federal authority ruling over them. Slavery was the issue of the time and NOT the principle.
More importantly-- Me, speaking this TRUTH is not an endorsement of slavery or even the idea of Confederacy. It's simply an acknowledgment of the truth, whether we like to hear it or not. We get nowhere by rejecting the truth and adopting an idiotic notion that doesn't comport with reality. You cannot absolve the North of the guilt for upholding slavery for 89 years by scapegoating the South. You cannot turn the Union into a bunch of Civil Rights Warriors who were fighting for equality against a racist South. That's a false picture of reality and I can't allow that to go unchallenged.