No, those that usurped and fought for those the states learned. There was no case made for seceding so it was simply a coup thus had no legitimate power. A coup that was unchallenged by the major of those states populations but still a coup.
I was looking thru a book published in the 1870s
that suggested "why was there a civil war" as a debate topic.
If they didnt know then, maybe certainty now is misplaced.
One hears a quite different pov on Taiwan independence
depending which side of the strait one is on.
For one, they both consider the othet to be the rebels.
And those dreadful American idependence fellows,
those traitorous rebels!
In the event, the American thing about self determination
is generally observed in the breach, and, as noted,
boundaries are determined by force.