We did not ‘’secede’’ from Britain. We declared ourselves free people with rights given to us by God, not by a degenerate monarchy that thought itself superior by dint of ‘’royal blood’’.
The South seceded from the Union in order to preserve an economic system based on the use of slave labor.
If states like Virginia, the Carolinas and Georgia could have known in the 1780s what would happen to them 80+ years later, they never would have ratified the Constitution in the first place. That right there is enough to convince me that they had every right to secede from the U.S.