Lat/Long: 40.0000, -89.0000
Created from the Indiana Territory on March 1, 1809, the Illinois Territory spanned all of modern Illinois and Wisconsin along with parts of Michigan and Minnesota. The capital was located in Kaskaskia. Illinois Territory ceased to exist on December 3, 1818, when Illinois became a state and the rest of the territory became part of the Michigan Territory.
"An Act for Dividing the Indiana Territory into Two Separate Governments," 3 February 1809, Statutes at Large of the United States 2 (1809): 514-16; "An Act to Enable the People of the Illinois Territory to Form a Constitution and State Government, and for Admission of Such State into the Union on an Equal Footing with the Original States," 18 April 1818, Statutes at Large of the United States 3 (1818): 428-31; "Resolution Declaring the Admission of the State of Illinois into the Union," 3 December 1818, Statutes at Large of the United States 3 (1818): 536; Newton Bateman and Paul Selby, eds., Historical Encyclopedia of Illinois (Chicago: Munsell, 1901), 255-58.