Trusty system (prison)
The prison warden controlled the prison completely.  Nobody from outside of the prison ever came in to see what was going on.  Because of this, nobody outside the prison knew what Parchman was really like.  For example, in 1911, the New York Times wrote an article congratulating the Mississippi prison system for figuring out how to keep people in prison and make money at the same time.  Also, because no outsiders ever came into Parchman, the conditions and abuse at the prison changed very little from the time it opened in 1903 until the Gates v. Collier case forced it to change.