Leavenworth, Kansas, the seat of Leavenworth County. It is in northeastern Kansas, on the Missouri River, about 20 miles (32 km) northwest of Kansas City. Leavenworth is the commercial center of a farm and livestock region and has light manufacturing industries. Fort Leavenworth, an army post with a large civilian work force, and a large veterans hospital are the city's leading employers. On the grounds of Fort Leavenworth are the U.S. Army Command and General Staff College; the Post Museum; and Leavenworth Prison, a federal penitentiary.

Leavenworth is the oldest city in Kansas. It was founded in 1854 by pro-slavery colonists who settled near the fort for protection against Indians. The city was incorporated in 1855. It has the council-manager form of government.

Population: 35,420.