[SC33]

The Union was very loosely held together at that point in time, and whether official policy or not, the states wielded the power. It is unfair to call great Southern warriors traitors.

[Clemenza]

Well, that Great Southern Warrior Andrew Jackson threatened to invade South Carolina and hang John Calhoun if the Palmetto State made good on its plans to leave the union 35 years earlier.

In other words, by 1861, it was largely understood what the Union was. The secessionists were tilting at windmills by then. Even Lee and Davis thought secession to be wrong up to the moment (in Lee's case) of Virginia's secession from the union.