certain Federal prisons i guess if theres enough of them that they can still be considered a threat.

I think things started to change within the state prisons during the late 60s into the 70s. One incident in particular demonstrates this.
Rahway Prison 1972, mafia kingpin Anthony "little pussy" Russo and his crew acquired some stolen narcotics that were taken from the prison hospital.These drugs were made cheaper for whites than they were to black inmates. Black inmate teddy gibson and his guys find this kind of discrimination no longer acceptable and decide to act.

Russo and several of his associates are jumped in the mess hall by Gibson and co.Russo is stabbed in his lower back along with rosario miraglia. Vince Fenick , Harry Schultz and Charlie heilig are also stabbed and piped.The next morning Mike Masucci is attacked by black inmates and has a chunk of his lip cut off.

No one died but it demonstrated the changing demographics and shift in power.