Post-prison years
Because the penitentiary cost much more to operate than other prisons (nearly $10 per prisoner per day, as opposed to $3 per prisoner per day at Atlanta),[27] and half a century of salt water saturation had severely eroded the buildings, then Attorney General Robert F. Kennedy ordered the penitentiary closed on March 21, 1963. In addition, citizens were increasingly protesting the environmental effects of sewage released into San Francisco Bay from the approximately 250 inmates and 60 Bureau of Prisons families on the island. That year, the United States Penitentiary in Marion, Illinois, on land, opened as the replacement facility for Alcatraz.