If they paid, equipped and protected them, then they had a substantial ongoing legal interest.
The Union couldn’t simply claim that it was theirs without just compensation. It was no more ‘theirs’ than it belonged to the South.
Calling up the state of Virginia to mobilize against the confederacy was an act of war. Until then, the Confederacy had done nothing more but assert that they wanted to leave the union - peacefully - and protect their borders (which, last I checked, includes the state of South Carolina.
Almost all of the fighting was fought on Confederate soil. If the Confederacy intended to subjugate the North, then why did they end up defending. Gettysburg is the only time in the entire civil war that the South fought on Northern territory above the mason dixon. In 4 years. That’s it.
Wrong, wrong, wrong, wrong, and wrong (at least you’re consistent ;-)