The Illinois Senate is the upper chamber of the Illinois General Assembly. The Senate met in Kaskaskia in 1818 and 1819, in Vandalia from 1820 to 1839, and in Springfield beginning in 1839.
Ill. Const. of 1818, art. II, § 1; Ill. Const. of 1848, art. III, § 1; John Clayton, comp., Illinois Fact Book and Historical Almanac 1673-1968 (Carbondale and Edwardsville: Southern Illinois University Press, 1970), 22-24.