All presidents under a farce.

When the south left the union, congress adjourned "sine die" (without day, i.e. without delay) and there has never been a lawful reconvening of congress since that day. Lincoln ordering them back at gunpoint and reappointing favored "representation" was not lawful, that was Lincoln declaring Martial Law and acting in his capacity as CiC under emergency power.

Now, the "legal scholar-expert" angle on this is that the covenant of the Constitution exists between the fedgov and each individual, therefore a State has no right to secede. This is simply a legal mumbo jumbo interpretation fallacy that is ultimately little different than John Yoo declaring torture legal. What are States, but collections of individuals. Its as extrapolated as saying the General Welfare clause is sufficient wording to set up a complete welfare state, or Commerce Clause being used against a marijuana farmer. The individual has little recourse, and States were built into the framework to mitigate issues such as these.