Political party strength in Illinois

The following table indicates the party of elected officials in the U.S. state of Illinois:
*Governor
*Lieutenant Governor
*Secretary of State
*Attorney General
*State Comptroller
*State Treasurer

The table also indicates the historical party composition in the:
*State Senate
*State House of Representatives
*State delegation to the U.S. Senate
*State delegation to the U.S. House of Representatives

For years in which a presidential election was held, the table indicates which party's candidate the state's electoral votes.

The parties are as follows: legend2|#CCEEFF|Democratic|border=1px solid #AAAAAA (D), legend2|#AACC99|Democratic-Republican|border=1px solid #AAAAAA (DR), and legend2|#FFB6B6|Republican|border=1px solid #AAAAAA (R).

For a particular year, the noted partisan composition is that which either took office during that year or which maintained the office througout the entire year. Only changes made outside of regularly scheduled elections are noted as affecting the partisan composition during a particular year. Shading is determined by the final result of any mid-cycle changes in partisan affiliation.