Penal labor in the United States is explicitly allowed by the 13th Amendment of the U.S. Constitution: "Neither slavery nor involuntary servitude, except as a punishment for crime whereof the party shall have been duly convicted, shall exist within the United States, or any place subject to their jurisdiction." ...
https://en.wikipedia.org/wiki/Penal_labor_in_the_United_States#:~:text=Penal%20labor%20in%20the%20United%20States%20is%20explicitly%20allowed%20by,place%20subject%20to%20their%20jurisdiction.%22