Wrong. They are slaves under the 13th amendment of the US, which explicitly allows slavery as punishment for a crime. Some more on this:
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
They're incarcerated while I presume you are not. Apart from all the involuntary aspects of prison life, inmates are not allowed to negotiate individually or organize for better pay and conditions. They cannot choose a different employer. The freedom to choose to go to the fire camp or stay within the prison under conditions designed to coerce them to work isn't really freedom. They're slaves.
Prisoners have limited rights to refuse anything. They are not fairly compensated for theor work and in other states the prisons “loan” prisoners to companies to do work who pay the prisons for this work.
It’s slavery. The USA never banned slavery for prisoners. It’s literally in the 14th amendment.