Incidentally, I was just two days ago in Montgomery, Alabama at the Equal Justice Initiative's museum documenting and memorializing the plight of enslaved people in the Americas. While not uniquely exploitative amongst all US states during the 2 century era of the legal slave trade, the post century of near complete lack of enforcement against the illegal slave trade, and the post half-century of transforming the slave trade into the prisoner-slave trade, this is true. Alabama--along with the other deep-South states--has been really bad about forced labor. I'd say it's more like 400 years of custom, with the first 150 years pre-dating the founding of the US, and the last 50 just being ignored because it's "only prisoners", with no introspection on just how those people became prisoners, or why what they did (or didn't even do) was considered a crime.