Jesus, that is an alarmingly plausible scenario. Presumably the planter class is more reviled than revered this time?
Love to read a story/TL on it 
Well, if you think about it, had McClellan captured Richmond via the Siege of Richmond the Confederacy's armies would have the following battles: First Bull Run, Wilson's Creek, Mill Springs, Pea Ridge, Fort Henry, Fort Donelson, New Orleans, Pittsburg Landing, Plum Run Bend.....a history of those battles which is designed to scapegoat Davis would focus on his tendency to neglect the West and his excessive interference in the East (truth of course has nothing to do with it) and so the idea is that had Southern troops had the chance to fight without Davis being involved, the first day of Pittsburg Landing would show their potential.
It'd be reading that history the wrong way, of course, but it'd still be there. As would arguably be slavery itself......and the reason for it taking until the 1890s is that the veterans of the war would know damned well they actually well and truly lost and would not initially be too willing to advocate support for this kind of thing again.