How would you have treated confederate leaders?

[TNF]

Trial by jury, of course. Juries composed of freed slaves and poor white sharecroppers drafted into the Confederate Army against their will.

And then of course, the hangman's noose.

[TNF]

Execution, without a doubt. The South got away with treason way too easily, and has had a chip on their shoulder ever since. Armed insurrection is not a silly little game, where you shake hands afterward. 

Yeah killing their leaders would've prevented that. . . .

Allowing them to live allowed them to organize and take back power in the South, thus undoing the entire Civil War for a ing century.