By the way, you are wrong again.---- USP Leavenworth is a civilian facility that houses 1,705 male inmates. It is one of three major prisons on federal land in Leavenworth County, Kansas. It is often confused with the United States Disciplinary Barracks (USDB), which is a maximum-security military facility adjacent to the Fort Leavenworth Army Base. Because it was built in the early 1900s, USP Leavenworth has a long history of notable inmates. They include former NFL quarterback Michael Vick (served 23 months for operating a dog-fighting ring), James Earl Ray (assassinated Martin Luther King Jr.), Samuel R. Caldwell (the first person to be convicted under the Marijuana Tax Act of 1937), and George “Machine Gun” Kelly (prohibition era gangster).