When the Government tells a state they cannot do anything, such as abolish slaver, that is against the principal of “States Rights”. So the argument that secession was drive by “states rights” is BS, because the Confederate Constitution would not permit member states to outlaw slavery. Yes the could amend the constitution to change that, but as written, Confederate states had no legal authority to end the institution of slavery.
Of course they did, Silly. Read the Constitution and quit wishing it doesn’t say what it does.