Leavenworth County

Leavenworth County, Kansas
County
Leavenworth County Courthouse in Leavenworth
Location in the U.S. state of Kansas
Kansas's location in the U.S.
Founded	August 25, 1855
Named for	Henry Leavenworth
Seat	Leavenworth
Largest city	Leavenworth
Area
• Total	469 sq mi (1,215 km2)
• Land	463 sq mi (1,199 km2)
• Water	6.1 sq mi (16 km2), 1.3%
Population (est.)
• (2016)	80,204
• Density	165/sq mi (64/km2)
Congressional district	2nd
Time zone	Central: UTC−6/−5
Website	LeavenworthCounty.org

Leavenworth County (county code LV) is a county located in the U.S. state of Kansas. As of the 2010 census, the county population was 76,227. Its county seat and most populous city is Leavenworth.

For many millennia, the Great Plains of North America was inhabited by nomadic Native Americans. From the 16th century to 18th century, the Kingdom of France claimed ownership of large parts of North America. In 1762, after the French and Indian War, France secretly ceded New France to Spain, per the Treaty of Fontainebleau.

In 1802, Spain returned most of the land to France, but keeping title to about 7,500 square miles. In 1803, most of the land for modern day Kansas was acquired by the United States from France as part of the 828,000 square mile Louisiana Purchase for 2.83 cents per acre.

In 1854, the Kansas Territory was organized, then in 1861 Kansas became the 34th U.S. state. In 1855, Leavenworth County was established, and is among the first 33 counties, which were formed by the first territorial government. It was named, as was its county seat, after Henry Leavenworth, an officer in the War of 1812.