Alexander County is the southern most and southwestern most county in the U.S. state of Illinois. As of the 2020 census, the population was 5,240. Its county seat is Cairo and its western boundary is formed by the Mississippi River. Wikipedia

Area: 253 mi²

Founded: 1819

Population: 6,011 (2020)

County seat: Cairo

Unemployment rate: 7.5% (Mar 2022)

Bond County is a county located in the U.S. state of Illinois. As of the 2020 census, the population was 16,725. Its county seat is Greenville. Bond County is included in the St. Louis, MO-IL Metropolitan Statistical Area. Wikipedia

Area: 383 mi²

Population: 16,520 (2020)

County seat: Greenville

Unemployment rate: 3.9% (Mar 2022)

University: Greenville University

Boone County is a county located in the U.S. state of Illinois. As of the 2020 census, the population was 53,448. Its county seat is Belvidere. Boone County is included in the Rockford, IL Metropolitan Statistical Area. Wikipedia

Area: 282 mi²

Founded: 1837

Population: 53,293 (2020)

County seat: Belvidere

Unemployment rate: 9.6% (Mar 2022)

Brown County is a county located in the U.S. state of Illinois. As of the 2010 census, the population was 6,937. Its county seat is Mount Sterling. Siloam Springs State Park is located partly in this county. Wikipedia

Area: 307 mi²

Founded: 1839

Population: 6,599 (2020)

County seat: Mount Sterling

Unemployment rate: 2.1% (Mar 2022)

Congressional district: 18th

Bureau County is a county located in the U.S. state of Illinois. As of the 2010 United States Census, the population was 34,978. Its county seat is Princeton. Bureau County is part of the Ottawa, IL Micropolitan Statistical Area, and the Hennepin Canal Parkway State Park is located partly in this county. Wikipedia

Area: 874 mi²

Founded: 1837

Population: 32,878 (2020)

County seat: Princeton

Unemployment rate: 5.1% (Mar 2022)

Calhoun County is a county in the U.S. state of Illinois. As of the 2010 census, the population was 5,089, making it Illinois’ third-least populous county. Its county seat and biggest community is Hardin, with a population of 801. Its smallest incorporated community is Hamburg, with a population of 99. Wikipedia

Area: 284 mi²

Founded: 1825

Population: 4,782 (2020)

County seat: Hardin

Congressional district: 13th

Unemployment rate: 4.1% (Mar 2022)

Cities: Hardin, Kampsville, Batchtown, Hamburg, Brussels

Carroll County is a county located in the U.S. state of Illinois. As of the 2010 census, the population was 15,387. Its county seat is Mount Carroll. Wikipedia

Area: 466 mi²

Founded: 1839

Population: 14,398 (2020)

County seat: Mount Carroll

Unemployment rate: 4.2% (Mar 2022)

Cities: Mount Carroll, Lanark, Savanna, Milledgeville, Thomson, Chadwick, Shannon

Cass County is a county located in the U.S. state of Illinois. As of the 2010 United States Census, the population was 13,642. Its county seat is Virginia. It is the home of the Jim Edgar Panther Creek State Fish and Wildlife Area. Wikipedia

Area: 384 mi²

Founded: 1837

Population: 12,324 (2020)

County seat: Virginia

Unemployment rate: 4.5% (Mar 2022)

Cities: Virginia, Beardstown, Chandlerville, Ashland, Arenzville

Champaign County is a county in the U.S. state of Illinois. As of the 2020 census, its population was 205,865, making it the 10th-most populous county in Illinois. Its county seat is Urbana. Champaign County is part of the Champaign–Urbana, IL Metropolitan Statistical Area. Wikipedia

Area: 998 mi²

Founded: 1833

Population: 210,006 (2020)

County seat: Urbana

Colleges and Universities: University of Illinois Urbana-Champaign, MORE

Christian County is a county located in the U.S. state of Illinois. As of the 2010 census, the population was 34,800. Its county seat is Taylorville. Wikipedia

Area: 716 mi²

Founded: 1839

Population: 32,705 (2020)

County seat: Taylorville

Unemployment rate: 4.9% (Mar 2022)

Clark County is a county located in the southeastern part of U.S. state of Illinois, along the Indiana state line. As of the 2010 census, the population was 16,335. Its county seat is Marshall. The county was named for George Rogers Clark, an officer who served in the American Revolution. Wikipedia

Area: 505 mi²

Founded: 1819

Population: 15,602 (2020)

County seat: Marshall

Unemployment rate: 4.8% (Mar 2022)

Cities: Marshall, Martinsville, Westfield, West Union, Moonshine

Clay County is a county in the U.S. state of Illinois. As of the 2010 United States Census, the population was 13,815. Since 1842, its county seat has been Louisville, in the center of the county's area. In 1950, the U.S. Census Bureau placed the mean center of U.S. population in Clay County. Wikipedia

Area: 470 mi²

Founded: 1824

Population: 13,217 (2020)

County seat: Louisville

Unemployment rate: 5.0% (Mar 2022)

Largest city: Flora

Cities: Louisville, Flora, Clay City, Xenia, Sailor Springs, Iola

Clinton County is located in the U.S. state of Illinois. As of the 2010 United States Census, the population was 37,762. Its county seat is Carlyle. In 1960, the United States Census Bureau placed the mean center of U.S. population in Clinton County. Wikipedia

Area: 503 mi²

Population: 37,549 (2020)

County seat: Carlyle

Unemployment rate: 3.0% (Mar 2022)

University: Kaskaskia College

Coles County is a county in Illinois. As of the 2020 census, the population was 46,863. Its county seat is Charleston, which is also the home of Eastern Illinois University. Coles County is part of the Charleston-Mattoon, IL Micropolitan Statistical Area. Wikipedia

Area: 510 mi²

Population: 51,065 (2020)

County seat: Charleston

Unemployment rate: 4.3% (Mar 2022)

Cities: Charleston, Mattoon, Ashmore, Lerna, Oakland, Humboldt, Trilla

Cook County is the most populous county in the U.S. state of Illinois and the second-most-populous county in the United States, after Los Angeles County, California. More than 40% of all residents of Illinois live within Cook County. As of 2020, the population was 5,275,541. Wikipedia

Area: 1,635 mi²

Population: 5.17 million (2020)

County seat: Chicago

Unemployment rate: 4.9% (Mar 2022)

Colleges and Universities: Northwestern University, MORE

Crawford County is a county located in the U.S. state of Illinois. As of the 2010 census, the population was 19,817. Its county seat is Robinson. Wikipedia

Area: 446 mi²

Founded: 1816

Population: 18,833 (2020)

County seat: Robinson

Unemployment rate: 4.2% (Mar 2022)

Cities: Robinson, Palestine, Oblong, Hutsonville, Flat Rock, Stoy, Annapolis, West York, Heathsville

University: Lincoln Trail College

Cumberland County is a county located in the U.S. state of Illinois. As of the 2010 census, the population was 11,048. Its county seat is Toledo. Cumberland County is part of the Charleston–Mattoon, IL Micropolitan Statistical Area. Wikipedia

Area: 347 mi²

Founded: 1843

Population: 10,787 (2020)

County seat: Toledo

Largest city: Neoga

Unemployment rate: 3.7% (Mar 2022)

Cities: Toledo, Greenup, Neoga, Jewett, Janesville

DeKalb County is a county located in the U.S. state of Illinois. As of the 2020 United States Census, the population was 100,420. Its county seat is Sycamore. DeKalb County is part of the Chicago-Naperville-Elgin, IL-IN-WI Metropolitan Statistical Area. Wikipedia

Area: 635 mi²

Population: 104,588 (2020)

County seat: Sycamore

Unemployment rate: 5.0% (Mar 2022)

Colleges and Universities: Northern Illinois University, Kishwaukee College, Debutantes School