From an excerpt available at NPR :

Quote
More than thirty thousand pages related to debt slavery cases sit in the files of the Department of Justice at the National Archives. Altogether, millions of mostly obscure entries in the public record offer details of a forced labor system of monotonous enormity.

Instead of thousands of true thieves and thugs drawn into the system over decades, the records demonstrate the capture and imprisonment of thousands of random indigent citizens, almost always under the thinnest chimera of probable cause or judicial process. The total number of workers caught in this net had to have totaled more than a hundred thousand and perhaps more than twice that figure. Instead of evidence showing black crime waves, the original records of county jails indicated thousands of arrests for inconsequential charges or for violations of laws specifically written to intimidate blacks—changing employers without permission, vagrancy, riding freight cars without a ticket, engaging in sexual activity— or loud talk—with white women.

The prisoners so obtained were bought, sold, leased, and to put it simply, enslaved.

The effect that these mundane realities had on the millions who lived under the threat of their consequences, combined with Jim Crow laws, lynchings, and a million other societal roadblocks to self betterment and any chance of a bit of the American dream are plain enough evidence that those who think the anger of Reverend Wright is based on playing the victim are nothing but racists or ignorant uncaring fools.