[AEMILIUS PAULUS]

The reason for no convictions of southern leaders being: (1) the National government did not want to exacerbate the hot feelings; (2) a court ruled that it was the states not the individuals that levied war(A Virginia Federal District Court if I remember correctly.)

[Verginius Rufus]

It was a principle of the common law (dating back to the Wars of the Roses) that a citizen could not be punished for obeying the government that was in control. I ran across that looking at some appeals court cases from the period right after the American Civil War (or whatever it should be called).

The 10th amendment could be construed as meaning that the states had a right to secede. I suspect that most of the men who voted in the state ratifying conventions assumed that secession was a potential option. After all, they were voting to secede from an existing arrangement, the Articles of Confederation.