Convict lease
At this time, the Southern states did not have much money, and they found that convict labor gave them a big source of revenue.  Contractors also made money off the system because they did not have to pay the prisoners the wages they would have to pay to white workers.  The Thirteenth Amendment to the United States Constitution had made slavery illegal  except as punishment for a crime.  So the states passed laws that would make it easy to convict innocent black people of crimes.  Once they were prisoners, they could be treated like slaves.  The states basically used this process as a way to continue slavery in the South.