So, your position is that the Southern states did not have the legal authority to seceed?
I suggest you read the New Hampshire or Texas state constitutions. Both states clearly retained the right to seceed. There are other examples.
Texas is a bit of a special case since it had a seperate existence as a sovereign nation something none of the other states ever had. Even the states of Virginia, N. Carolina, S. Carolina, and Georgia had no right to secede since the Union was created to be perpetual. There are arguments for their right to secede which are based on false premises and historical untruths. These are refuted on every one of these idiotic threads but the Defenders of Slaveocracy never allow logic and truth to stand in the way of their lies.
The other states rebelling were created by the U.S. buying their territory from other nations and thus, had even less pretensions to the right to secede.
Just see what Andy Jackson thought about this "right" or Madison.