ATC had a piece about Colorado agriculture using prison labor to make up for a shortage of seasonal workers. As I listened to the report I kept thinking that its not really fair to report on prison labor without contextualizing it in the current growth of the prison industrial complex and the horrific history of convict leasing.
A brief bit of searching will turn up some fascinating history such as this resource from Florida, the state I was born and raised in, or this general history of the practice. In fact, even NPR has covered convict leasing a few times in the past.
As far as the current prison system, it would have been interesting to hear from someone at Critical Resistance or the Prison Activist Resource Center which has a link to information on prison labor.