The American Correctional Association (ACA), formerly known as the National Prison Association, is the oldest and largest international correctional association in the world. Approximately 80 percent of all state departments of corrections and youth services are active participants. Also included are programs and facilities operated by the Federal Bureau of Prisons and the private sector. ACA accredits over 1,500 prisons, jails, community residential centers (halfway houses) and various other corrections facilities in the U.S. using their independently published Standards manuals. - Source: Wikipedia