I mentioned Douglas Blackmon's excellent book, Slavery by Another Name: The Re-Enslavement of Black Americans from the Civil War to World War II once before and I'm glad to learn that Bill Moyers featured it on his show recently. Here's a bit of the transcript:

DOUGLAS BLACKMON: Vagrancy. So, vagrancy was a law that essentially, it simply, you were breaking the law if you couldn't prove at any given moment that you were employed. Well, in a world in which there were no pay stubs, it was impossible to prove you were employed. The only way you could prove employment was if some man who owned land would vouch for you and say, he works for me. And of course, none of these laws said it only applies to black people. But overwhelmingly, they were only enforced against black people. And many times, thousands of times I believe, you had young black men who attempted to do that. They ended up being arrested and returned to the original farmer where they worked in chains, not even a free worker, but as a slave.

BILL MOYERS: And the result, as you write, thousands of black men were arrested, charged with whatever, jailed, and then sold to plantations, railroads, mills, lumber camps and factories in the deep South. And this went on, you say, right up to World War II?

DOUGLAS BLACKMON: And it was everywhere in the South. These forced labor camps were all over the place. The records that still survive, buried in courthouses all over the South, make it abundantly clear that thousands and thousands of African-Americans were arrested on completely specious claims, made up stuff, and then, purely because of this economic need and the ability of sheriffs and constables and others to make money off arresting them, and that providing them to these commercial enterprises, and being paid for that.

It's a fascinating book, and does a lot to put contemporary issues in an important but essentially forgotten context. See more here.