When America is attacked those who defend it are patriots. Those who join the enemy are Traitors. Secessionists ATTACKED the US. Not the other way around. There is no doubt that the US has the right to suppress insurrections. It is clearly stated. Nor is there any doubt that this was an insurrection. Trying to cover that FACT with declarations from illegal assemblies would only work with Jackson jurors. No state can change the Constitution unilaterally. Nor can it withdraw without being allowed to do so via constitutional amendment.
James Madison explained to Alexander Hamilton that there could be NO conditional ratification of the Constitution with a right to withdraw later. He stated "Once in the Union Always in the Union." Otherwise it made no sense even to bother with creating a Constitution and a Union if it had no more legal standing than a Moslem marriage.
Your first loyalty should be to your HOME. If you fight against the land that bred you, that is the WORST sort of Traitor.
My home is Texas, Robert E. Lee's was Virginia.