Going to prison means partially relinquishing your civil rights, but the United States constitution is supposed to ensure prisoner civil rights. These laws are in place to protect the rights of even the most hardened criminals and inmates who can be maltreated, punished, or abused by the system.
The United States has the highest incarceration in the world, with a black person six times more likely to be incarcerated than a white man. It is also the only democracy in the world that has no definite body established to monitor prison conditions or the rights of the prisoner. Whether it is to be treated fairly or protect their health and safety, prisoners have rights, and it is time you knew them.