Where? The definition. Rebellion is defined as "open, armed, and usually unsuccessful defiance of or opposition to an established government.
You haven’t established the feds right to force a state to stay in
If their act of secession is done illegally then it's rebellion, nothing more and nothing less.
Whereas Jefferson laid the ground work to leave
If your talking about the Declaration of Independence that, too, was done via rebellion. The difference being that the Founding Fathers won their rebellion and the southern states did not.
you’re missing the points. I said nothing about armed and you turned it into a rebellion. The military option was exercised by the feds to keep the southern states in the union.
Secondly you can’t establish a law that prevents their succession yet you refer to it as illegal. Since there is no power given to the feds, the tenth amendment would allow the states to make the decision to leave or not.