Both the death penalty, and a system of slave labor camps, are allowed at the federal level:

• The US currently operates a system of slave labor camps, including at least 54 prison farms involved in agricultural slave labor. Outside of agricultural slavery, Federal Prison Industries operates a multi-billion dollar industry with ~ 52 prison factories , where prisoners produce furniture, clothing, circuit boards, products for the military, computer aided design services, call center support for private companies. 1, 2, 3