Jefferson Davis didn’t have a ‘country,’ he led a collection of sovereign states that had a right to seceed that was recognized as unalienable by our founders.
Essentially, he was a victim of treasonous crime much like we are today.
Certainly the states had a right to seceed. The terms and methods were open to debate, doubt, and controversy.
And Controvery between states, or between a state and the federal government is to be resolved by law, with the SCOTUS as original jurisdiction.
But that wasn’t good enough for the Slave Power. They had to start a war. Then they lost, and that isn’t good enough for their modern day idolators.