Of course they had no legal right to declare independence.
They nowhere claimed they did. In colonial America, all Law flowed from the King in Parliament.
The Founders based their declaration not on Law, but on moral principles, overriding Law by Revolution, which is by definition the abandonment of Law for more direct action. (Hopefully with Law to be reinstated at some later date on a more sound footing.)
As Lee and other southern leaders recognized, the South had a similar moral right to revolution, although weakened by their revolution being for the purpose of denying independence to others.
But legality? Nonsense. When the southern states seceded, they rejected the legal procedures set up by the Constitution to settle differences. That's an act of Revolution, not one of Legality.
I eagerly await anybody who can prove the Founders ever claimed a Legal right for what they did, except insofar as they justified Revolution by an appeal to unwritten Natural Law.
>>the colonies had no legal right to present the Declaration of Independence to the legal ruler of those colonies.
>>Of course they had no legal right to declare independence.
I worded that poorly. My point was that the Confederacy had AS MUCH right to rebel as the colonists: legal, moral, or otherwise. We never speak of the American Revolution as a civil war (even though it was from April 1775 to July 1776) and the failed Second Revolution was no civil war either.