They used that part of the 13th that said “Well, except prisoners, those can be slaves.” Local law enforcement rounded up former slaves on trumped up charges and leased them back to the same plantation owners they were freed from. Only now if they escaped they were “escaped criminals” and they could count on even northern law enforcement returning them. The US is still a pro-slavery country and will be as long as that part of the 13th amendment stands.

Reminds me of that time the Federal government granted land parcels to a bunch of former slaves (using land from plantations) and then rescinded them again.