The years after the war saw both black and white criminal activity increase, which was a problem, because most prisons had been destroyed during the war. The states took a look at the massive influx of prisoners in their hands, surreptitiously glanced at each other ... and started leasing them to wealthy planters and industry big shots as free, forced labor.
This system, known as convict lease, quickly became one of the most lubed-up loopholes in history. Some of the criminals caught up in the machine were white, but an estimated 80 to 90 percent were black, because of fucking course they were. Many former slaves found that freedom was the worst thing that could have happened to them, as the police got hold of them and piled on enough arbitrary charges to put them into "totally not slavery" forced labor for years, toiling under essentially the same assholes who had owned them during their slave days.
"If you love someone, set them free. If you force them to come back shackled, kicking, and screaming, it was meant to be."
The conditions were generally much worse, too. There was a lot less financial incentive to keep a prisoner alive than a slave, so living conditions of prisoners under convict lease tended to be abysmal. In some cases, the death rate was as high as 40 percent. But the public was okay with it, because hey, that's what they get for committing crimes! We're not exploiting a racial and economic class, we're punishing the bad guys!