Now back up and prove it's nonsense.
..... they violated the Constitution in their acts of unilateral secession.
No, they didn't. Make a treaty, unmake a treaty -- a sovereign isn't someone a judge can overrule.
But you are recalcitrant and slothful, so let's try it this way:
Who is the sovereign of the United States of America? What is his name, where does he live?
To put it a little more bluntly: Who's your daddy, servile belly-crawler? Who do you crawl for?
Yes they did. And the Constitution does not give the states to make a treaty with foreign countries or other states.
To put it a little more bluntly: Who's your daddy, servile belly-crawler? Who do you crawl for?
Certainly not you.