Information about convict leasing can be found in Slavery by Another Name: The Re-enslavement of Black People in America from the Civil War to World War II by Douglas Blackmon.
https://archive.org/details/slaverybyanother2008blac
For a more detailed explanation about this meme, please see:
https://www.reddit.com/r/HistoryMemes/comments/121qyyw/comment/jdmy1a8/