FCI Leavenworth, in northeast Kansas, sits on ground with an unusually long institutional history for the federal system. Congress transferred the land from the War Department to the Justice Department in 1897 to build a federal penitentiary, and the first prisoners arrived in 1903, with the first cellhouse completed in 1906 and the full complex not finished until the mid-1920s. For decades it operated as USP Leavenworth, and at one point it was the largest maximum-security prison in the entire United States — a status it held until 2005, when it was downgraded to medium-security and restructured as FCI Leavenworth, now housing roughly 1,600-1,700 male inmates plus a satellite minimum-security camp. It's the oldest of three federal prisons that were built in Leavenworth County (a cluster that also includes a military prison and other correctional facilities), giving the town a long-standing identity tied to federal corrections. Over its more than a century of operation, the historic penitentiary held a range of well-known inmates over the decades. For families, it's a facility with genuine institutional depth and history, now operating at a somewhat lower security tier than its famous past.