Fort Leavenworth, KS

ZIP code 66027 encompasses Fort Leavenworth, a historic Army installation in Leavenworth County, Kansas. Established in 1827, Fort Leavenworth is the oldest active United States Army post west of Washington D.C. It is home to the United States Disciplinary Barracks, the only maximum-security prison for military personnel, as well as the Buffalo Soldier Monument and the Fort Leavenworth National Cemetery.