The period following the Civil War saw bad conditions surrounding military prisons. Prisons were inadequate and held a mixture of long term and minor offenders. The prisons also required a large portion of commanding officer's time who did not always have the proper training to deal with offenders. Punishments were not uniformly administered and often unnecessary.
Major Thomas F. Barr, Judge Advocate of the Department of the East, submitted a report to the Secretary of War in which he described the unsatisfactory conditions of the military prisons. The U.S. military established a new system based on British military prisons. An act of Congress was approved on March 3, 1873 to establish a federal military prison. The original location for the prison was Rock Island, Ill. However, concerns about interference with the Ordnance Depot manufacturing changed the site. Fort Leavenworth was then chosen as the location for the U.S. Military Prison. It kept this name until 1915 when it was renamed the U.S. Disciplinary Barracks. Construction of the prison began in 1874 and was completed in 1921.
Congress funded an expansion of the prison in 1908 to include a large development known as "the Castle." It consisted of a central stack with cell blocks radiating outwards. The finished prison consisted of 1,200 cells, four cell houses, a dining area, gymnasium, inmate radio station, offices, mail room, library, and death chamber.
Vocational programs began at the USDB in 1877 with the making of Army shoes and boots to provide useful occupation and opportunity for prisoners to gain trade skills. This led to the development of other vocational activities for the prisoners such as auto mechanics, barbering, bee keeping, blacksmith activities, carpentry, soap making, plumbing, welding, agricultural undertakings, and more. In 1880 the prison established an educational system. All prisoners who could not read or write were required to attend.
The Castle officially closed in 2003 and a new USDB facility opened north of the original location in 2002. Members of the 15th MP Brigade staff the prison.