Legislative responsibility for the Illinois Territory after it became a territory of the second grade was invested in a bicameral General Assembly composed of an elected House of Representatives and a Legislative Council of House members nominated by their peers and chosen by the U. S. Congress. This body replaced the Council of Revision of the early territorial period in 1812, and was suceeded by the present House and Senate General Assembly after the territory became a state in 1818.
From the description of Legislative records, 1813-1817. (Illinois State Archive). WorldCat record id: 35641010