The state of Wisconsin in the United States has 72 counties. The land that eventually became Wisconsin was transferred from British to American control with the 1783 signing of the Treaty of Paris. It was an unorganized part of the Northwest Territory until 1802 when all of the land from St. Louis north to the Canadian border was organized as St. Clair County. When Illinois was admitted to the union in 1818, Wisconsin became part of the Territory of Michigan and divided into two counties: Brown County in the northeast along Lake Michigan and Crawford County in the southwest along the Mississippi River. Iowa County was formed in 1829 from the Crawford County land south of the Wisconsin River. Brown County's southern portion was used to form Milwaukee County in 1834. The state of Wisconsin w