Eastern State Penitentiary. Once the most famous and expensive prison in the world. Prisoners such as bank robber Slick Willie Sutton and gangster Al Capone were held inside its innovative wagon wheel design. Eastern State's revolutionary system of incarceration, dubbed the "Pennsylvania system" or separate system, encouraged separate confinement (the warden was legally required to visit every inmate every day, and the overseers were mandated to see each inmate three times a day) as a form of rehabilitation.
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