I don’t hate him. It’s just that he was literally a traitor and broke sacred oaths he took. I don’t find anything about him admirable.
I think the USA was a different entity back then. As I recall when Lee was asked if he would accept the Union Army commander position, his reply was, “I cannot go against Virgina”. Loyalty back then was much more state than union oriented,
I think it is difficult for us to understand the political/social situation on the ground back then. Was the civil war ultimately about Slavery? Ultimately yes, though it is somewhat convoluted.
Would the men who died for the Confederacy have sacrificed their lives solely for the institution of Slavery? I doubt it. I think there was enough convoluted issues back then for a soldier to be for the South but neutral or against slavery.