Was the Revolution an insurrection?
The colonies were governed by an empire which restricted self-government and political rights.
You don't have to justify morally what the colonists did. You have to cite the law that allowed them to do it.
What law allowed the Colonists to secede from the United Kingdom? Isn't that your argument for the Confederates? That they had no legal right to leave?
A revolution is only such when an insurrection succeeds.
Possession of the colonies was just a claim by Brits determined by the Right of Conquest. The violations of the “Rights of Englishmen” was one of the main causes of our revolt.
This is a completely different from an insurrection which revolts against a legitimate government proceeding from the consent of the governed.
The War came about entirely because of Southern fears about slavery. Even as you showed there was no threat except becoming less powerful as new states were added.
These states had formed a contractual relationship which cannot be dissolved on a whim, particularly since the rights of the South were never threatened.
This contract could not be unilaterally abrogated and treated like a Moslem marriage.