I don't know about other States but I have looked at my State's (Indiana) Monument For Statehood, the request, and the Enabiling Act, the grant, and there is no language preventing Indiana from leaving the Union at any time.
Check the Constitution.
I don't know about other States but I have looked at my State's (Indiana) Monument For Statehood, the request, and the Enabiling Act, the grant, and there is no language preventing Indiana from leaving the Union at any time.
What about some sort of common law? A government that consists of states that come and go as they please when they please couldn't be expected to be a very credible government, could it? Take marriage as an analogous relationship. One spouse can't unilaterally terminate the marriage. A divorce must be secured from the state. The Declaration of Independence acknowledges that the decision to "dissolve the political bands" is a monumental one; furthermore, the signers clearly understood that they were committing, in the eyes of the British, treason. I think a judge could easily be persuaded to conclude, on the basis of the common law at the time, that secession was treasonable at the time of the nation's founding and no law altered that afterwards; thus, a state has no right to secede without the blessing of the remainder of the nation. That doesn't mean a state can't try, but if you're going to overthrow the king, make sure you kill him.