The first prison built according to the separate system was the Eastern State Penitentiary in the United States in 1829, a design that was later copied by over 300 prisons worldwide. Common features of a separate system prison include a central hall, with several (from four to eight) radiating wings of prison blocks, separated from the central hall and from each other by large metal bars. While all the prison blocks are visible to the prison staff positioned at the centre, individual cells cannot be seen, unlike panopticon prisons, unless the staff enter individual prison blocks.
The spaces between the prison blocks and the prison wall are used as exercise yards. When the separate system was first introduced, prisoners were required to be in solitary confinement even during exercise; as a result panopticon-style structures were erected inside these yards, in which a guard post was surrounded by tiny, cell-like, one-person exercise "yards". By the end of the 19th Century these structures were removed in favour of more open - if communal - exercise yards.
Many of these separate system prisons from the 19th Century continue to house prisoners to this day; moreover the separate system continues to influence modern prison architecture.
Designers of these penal institutions drew heavily on monastic solitary confinement in order to both destroy the identity of the inmate (and thus make him easier to control) and to crush the "criminal subculture" that flourished in closely-populated prisons.
Prisoners incarcerated in separate system prisons were reduced to numbers, their names, faces and past histories eliminated. The guards and warders charged with overseeing these prisoners knew neither their names nor their crimes, and were prohibited from speaking to them. Prisoners were hooded upon exiting a cell, and even wore felted shoes to muffle their footsteps. The result was a dumb obedience and a passive disorientation that shattered the "criminal community."