They fought against the Republic of the United States. Lee deserves honor for the way he surrendered and you are right, he worked to reunify the Country.
They fought for the State of Virginia.
I don’t know how Jackson felt about Session, but Ashby opposed it and that Lee declined command of the North before accepting command of the South shows him to be a military man of principle who largely kept his politics to himself.
Sic Semper Tyrannus.
As for the Republic, such that it is, and such that it was, I doubt they were opposed to it as originally conceived, and would have been happy enough under other circumstances to fight for it as originally conceived. The Union, nest to our liberties most dear.
That’s your opinion. In their eyes Lincoln destroyed the Republic because he wouldn’t let the states secede.
After causing the deaths of 700,000 Americans.
Honestly how in the Hell do you people sqaure yourselves by calling yourself conservative Republicans all the time wailing a Greek Chorus for a bunch of treasonous Southern Democrats?