What??? Firstly Lincoln couldn't have done anything to the post-war South, seeing as he was assassinated right after Lee's surrender but before the ACW even ended and the Confederacy itself wasn't totally defeated until it collapsed entirely in May of 1865, a month after his death.
Secondly, Deep South American whites were probably the most leniently treated rebellious populace in all of history. They weren't massacred in droves, they weren't imprisoned or deported to an Alaskan/Arizonan gulag, they certainly weren't enslaved themselves, and they even got to restore their power like a decade later. I've said as much before but apparently it must be repeated: in the same timeframe as the ACW something like 70,000 Poles got deported after the failure of the January Uprising against Russia (on top of tens of thousands killed in the rebellion itself), ~800,000 Indians died in the suppression of the Sepoy Rebellion of 1857 by the British, and 30-100 million Chinese were getting killed over the course of the Taiping Rebellion's suppression by the Qing dynasty, among a bunch of other outrages performed in attempts to break rebellious populations elsewhere.
Had they rebelled against any other imperial power in any other time in history they'd probably be looking at even worse than that. The same Jacobin revolutionaries Thomas Jefferson was fond of responded to the Vendée uprising with a pseudo-genocidal campaign of massacres & rapine that left 200,000 dead. And the Roman Republicans who the Founding Fathers looked up to responded to Spartacus' slave rebellion by crucifying 6,000 slaves between Rome & Capua, while their Imperial successors were the reason why there wasn't a Jewish nation in Israel until 1948.
You're out of your mind if you think they were 'spat upon' and treated harshly by the US government post-war, just because...well, why? Because CRT (which I don't deny is complete bullshit) has been a thing and Hollywood celebs have held 'flyover country' in disdain for the past 60 years, basically a blink of an eye in macrohistorical terms? I sincerely recommend getting some perspective and also thickening your skin here. Like holy shit, 'massacre everyone who looks like the rebels regardless of guilt' was how Southern American whites themselves responded to Nat Turner's slave revolt a full 30 years before the outbreak of the ACW!