This chapter discusses the history and development of jails and prisons in America. It describes the early conditions of colonial jails and how reforms led to distinct models like the Walnut Street Jail and Eastern State Penitentiary. Contemporary jails include federal, county, and municipal facilities that serve as short-term holding places. State prisons house convicted felons in minimum to maximum security facilities based on classification. Federal prisons are run by the Bureau of Prisons. Prison populations face challenges regarding health, mental illness, and special groups. Privatization was pursued but caused professionalism problems.