Congressional district · Boundaries of the 119th Congress

Illinois's 12th district

Illinois's 12th district has 749,731 residents on 14,016 mi² of land. It is represented by Mike Bost (R-IL-12). Federal contract obligations attributed to it reached $684.6M in FY2026.

Residents
749,731
Land area
14,016 mi²
Counties
34
Representative
Mike Bost
Open in the Congress explorer
Map of Illinois's 12th district within Illinois

Members for this district

Members who held this seat while these boundaries were in force, newest first.

Senators

The state's senators today, or on the last day of these boundaries for an older plan.

Counties

Share of the district's residents living in each county, and share of the county's residents living in the district (2020 census tracts weighted by their overlap).

  1. St. Clair County13% of the district · 38% of the county
  2. Williamson County8.9% of the district · 100% of the county
  3. Jackson County7.1% of the district · 100% of the county
  4. Franklin County5.0% of the district · 100% of the county
  5. Marion County4.9% of the district · 100% of the county
  6. Clinton County4.9% of the district · 100% of the county
  7. Jefferson County4.9% of the district · 100% of the county
  8. Monroe County4.7% of the district · 100% of the county
  9. Effingham County4.6% of the district · 100% of the county
  10. Randolph County4.0% of the district · 100% of the county
  11. Saline County3.1% of the district · 100% of the county
  12. Perry County2.8% of the district · 100% of the county
  13. Crawford County2.5% of the district · 100% of the county
  14. Union County2.3% of the district · 100% of the county
  15. Wayne County2.1% of the district · 100% of the county
  16. Richland County2.1% of the district · 100% of the county
  17. Clark County2.0% of the district · 100% of the county
  18. Lawrence County2.0% of the district · 100% of the county
  19. Massac County1.8% of the district · 100% of the county
  20. Washington County1.8% of the district · 100% of the county
  21. White County1.8% of the district · 100% of the county
  22. Johnson County1.8% of the district · 100% of the county
  23. Clay County1.7% of the district · 100% of the county
  24. Coles County1.5% of the district · 25% of the county
  25. Wabash County1.5% of the district · 100% of the county
  26. Cumberland County1.4% of the district · 100% of the county
  27. Jasper County1.2% of the district · 100% of the county
  28. Hamilton County1.1% of the district · 100% of the county
  29. Edwards County0.8% of the district · 100% of the county
  30. Pulaski County0.7% of the district · 100% of the county
  31. Alexander County0.7% of the district · 100% of the county
  32. Gallatin County0.6% of the district · 100% of the county
  33. Pope County0.5% of the district · 100% of the county
  34. Hardin County0.5% of the district · 100% of the county

Federal contracts

Contract obligations attributed to the district by each action's county and its award's ZIP code (land shares through census tracts); an estimate where ZIP codes cross district lines.

Obligations · FY2026
$684.6M
Per resident
$913
Rank in Illinois
5 of 17
Contract actions
1,873
New awards: 643

By fiscal year

  1. 1.2BFY2017
  2. 1.1BFY2018
  3. 966MFY2019
  4. 1.1BFY2020
  5. 1.5BFY2021
  6. 1.4BFY2022
  7. 1.3BFY2023
  8. 1.6BFY2024
  9. 1BFY2025
  10. 684.6MFY2026

Top buyers

  1. USTRANSCOM$334.5M49%
    Department of Defense
  2. Department of the Air Force$130.3M19%
    Department of Defense
  3. Department of the Army$94.5M14%
    Department of Defense
  4. Defense Information Systems Agency$38.5M5.6%
    Department of Defense
  5. Defense Logistics Agency$21.1M3.1%
    Department of Defense
  6. Federal Prison System / Bureau of Prisons$18.9M2.8%
    Department of Justice
  7. Department of Veterans Affairs$17.6M2.6%
  8. Federal Acquisition Service$17.3M2.5%
    General Services Administration

Top recipients

  1. CACI, INC. - FEDERAL$62.8M9.2%
    7 awards
  2. SCIENCE APPLICATIONS INTERNATIONAL CORPORATION$46.8M6.8%
    4 awards
  3. UNCOMN LLC$43.6M6.4%
    22 awards
  4. FM MCCARTHY, LLC$35.6M5.2%
    1 award
  5. GENERAL DYNAMICS ORDNANCE & TACTICAL SYSTEMS, INC.$30.6M4.5%
    19 awards
  6. BELLEVILLE SHOE MANUFACTURING COMPANY$18.1M2.6%
    24 awards
  7. DECISIONPOINT CORPORATION$15.5M2.3%
    5 awards
  8. THE BOEING COMPANY$14.7M2.1%
    3 awards
  9. AGILE-BOT II LLC$14.5M2.1%
    1 award
  10. ECS FEDERAL, LLC$13.7M2.0%
    1 award

Other boundaries

District lines change between plans; each plan keeps its own page.

Sources and method

Every figure on this page traces to these records.

  • Congressional district boundaries and relationship files (U.S. Census Bureau)U.S. Census Bureau, Cartographic Boundary Files (congressional districts) and 2020 relationship files · release cd116+cd118+cd119 · loaded Oct 3, 2026 · license: Public domain (U.S. Government work, 17 U.S.C. § 105)
  • Members of Congress, their terms, committees and identifiers (The @unitedstates project (from the Biographical Directory of the U.S. Congress, the House and the Senate))unitedstates/congress-legislators: legislators, committees and current committee membership · data current to Oct 3, 2026 · loaded Oct 3, 2026 · license: CC0 1.0 (public domain dedication)
  • ZIP code (ZCTA) to congressional district crosswalk (U.S. Census Bureau)U.S. Census Bureau, 2020 relationship files (ZCTAs, tracts and congressional districts); shares computed by Analisa · release 2020 · loaded Oct 3, 2026 · license: Public domain (U.S. Government work, 17 U.S.C. § 105)
  • Federal contract transactions (Federal Procurement Data System) (U.S. Department of the Treasury, USAspending.gov)USAspending.gov, prime award contract transactions (FPDS) · data current to Oct 3, 2026 · loaded Oct 3, 2026 · license: Public domain (U.S. Government work, 17 U.S.C. § 105)
  • Money and votes are shown side by side; neither explains the other.