I just read "Slavery By Another Name" by Douglas A. Blackmon. It is about the re-enslavement of black americans from the Civil War to World War II and is eye opening, jaw dropping and totally overwhelming and I recommend you read it.
It seems that the southern whites could not make a go of it after the slaves were "freed" after the Civil War so developed a system of peonage or forced slavery whereby a black would be arrested on a trumped up charge and when he couldn't pay the fine, a big powerful white man would kindly pay it and the man was his for life.
If you are interested in this subject matter and learning the REAL history of America read it.
I can't believe we put ourselves up as the land of the free after reading this book.