When did supermax prisons begin to emerge throughout the united states?

Whereas the first prison of this type in the U. S. was Alcatraz, which was opened in 1934, it still wasn't called supermax prison. The first officially recognized supermax prison (i. e. prison with maximum security) was established in 1984 in Marion, after two inmates of Federal Penitentiary killed two guards. That prison was transformed into a supermax facility, which was followed by dozens of other prisons throughout the States.