Illinois General Assembly
The Illinois General Assembly is the bicameral state legislature of Illinois, vested with the state's legislative power under Article IV of the Illinois Constitution of 1970.[1] It comprises a Senate of 59 members, each representing one of 59 legislative districts and serving staggered four-year terms, and a House of Representatives with 118 members elected from 118 representative districts for two-year terms.[1] [2] The General Assembly convenes annually in Springfield at the Illinois State Capitol to enact statutes, approve the state budget, confirm gubernatorial appointments, and override executive vetoes by a three-fifths majority in each chamber.[3] [4] Established by Illinois's first constitution upon statehood in 1818, the legislature has undergone structural changes, including the abolition of multi-member districts and cumulative voting for the House in 1980 following the adoption of the current single-member district system.[4] Its powers include the ability to block administrative regulations and propose constitutional amendments, subject to voter approval.[1] As of the 104th General Assembly in 2025, Democrats maintain supermajorities, holding 78 seats in the House to Republicans' 40 and a substantial majority in the Senate, enabling unified party control over legislative priorities amid ongoing debates over fiscal policy and redistricting practices that have favored the majority party.[5] [6] Historically, the body has been marked by internal leadership struggles and late-session rushes to pass omnibus bills, contributing to criticisms of opaque processes, though it has also addressed key state issues such as pension reforms and infrastructure funding.[7] [8] Notable alumni include Abraham Lincoln, who served in the House from 1834 to 1842, advocating for internal improvements and banking reforms during his tenure.[9]Historical Development
Establishment and Early Evolution
The Illinois General Assembly was established through the state's first constitution, ratified on August 26, 1818, which vested legislative authority in a bicameral body comprising a Senate and a House of Representatives, both elected by qualified voters and modeled on the structure of the U.S. Congress to ensure separation of powers and representation.[10] This framework built upon the Illinois Territory's legislative experience, where an elected bicameral assembly had operated since 1812 under provisions of the Northwest Ordinance of 1787, which mandated a lower house elected by popular vote and an upper council appointed initially but later adapted for territorial governance.[11][12] The 1818 document specified an initial House membership of no fewer than 27 nor more than 36, with the Senate sized at one-third to one-half thereof, resulting in 28 representatives and 14 senators for the inaugural session based on early population enumerations from the territory's counties.[10] The first session convened on October 5, 1818, in Kaskaskia, the territorial and initial state capital, where lawmakers qualified Governor Shadrach Bond and organized essential state functions, including the creation of circuit courts and provisions for county governance amid a sparse population of approximately 40,000. Early legislative priorities centered on pragmatic state-building, such as ratifying land grants from federal cessions, authorizing surveys for internal improvements like roads, and enacting statutes to regulate elections and taxation, reflecting the frontier economy's reliance on agriculture and migration rather than expansive policy ambitions.[3] These sessions, held annually thereafter until constitutional adjustments, adapted Northwest Ordinance principles of limited government and public land management to Illinois' transition from territory to statehood, completed with congressional admission on December 3, 1818.[13] As the state grew, the General Assembly's operations evolved with the relocation of the capital to Vandalia in 1820, where subsequent sessions addressed expanding infrastructure needs, including river navigation improvements and militia organization, while maintaining the bicameral form without immediate alterations to chamber sizes.[14] This period marked a foundational emphasis on empirical governance tailored to demographic realities, with lawmakers drawn primarily from settler communities and focused on enabling economic settlement over ideological reforms.Changes in Size and Apportionment
The Illinois General Assembly's size expanded significantly in the 19th century to reflect rapid population growth following statehood. The 1818 constitution initially fixed the House of Representatives at 28 members and the Senate at 14 members, apportioned based on counties with adjustments after the first census.[10] The 1848 constitution responded to demographic shifts by allowing the House to range from 70 to 100 members and the Senate from 19 to 33 members, with reapportionment tied to federal censuses every four years to account for settlement patterns.[15] By the 1870 constitution, amid further urbanization and agricultural expansion, the legislature standardized at 153 House seats and 51 Senate seats, structured as 51 multi-member districts electing one senator and three representatives each, with decennial reapportionment mandated but often neglected in practice.[16]| Constitution Year | House Seats | Senate Seats | Apportionment Basis |
|---|---|---|---|
| 1818 | 28 | 14 | County-based, post-census adjustment[10] |
| 1848 | 70–100 | 19–33 | Census-driven expansion for population growth[15] |
| 1870 | 153 | 51 | 51 districts, three representatives per district[16] |