Cook County Illinois : Ask Biography

Administration

Full name

Cook County, Illinois

Official name

Cook County, Illinois

Settlement type

County

Country

United States

State

Illinois

Region

Northern Illinois

Metro area

Chicago metropolitan area

Incorporated

January 15, 1831

Named for

Daniel Cook

Government

County seat

Chicago

President

Toni R. Preckwinkle

Geography

Total Area

1635 sq mi (4234.7 km2)

Land Area

946 sq mi (2450.1 km2)

Water Area

689 sq mi (1784.5 km2)

Demography

Density (pop.)

2119.6/km² (5491.3/sq mi)

Other information

Time zone

Central Standard Time (UTC-6)

- Summer (DST)

Central Daylight Time (UTC-5)

Home | County | Cook County Illinois

Cook County is a county in the U.S. state of Illinois, with its county seat in Chicago. It is the second most populous county in the United States after Los Angeles County. The county has 5,194,675 residents, which is 40.5% of all Illinois residents. Cook County's population is larger than that of 29 individual U.S. states and the combined populations of the seven smallest US states. There are over 130 incorporated municipalities in Cook County, the largest of which is Chicago, which makes up approximately 54% of the population of the county. That part of the county which lies outside of the Chicago city limits is divided into 30 townships. Geographically the county is the fifth largest in Illinois by land area and shares the state's Lake Michigan shoreline with Lake County. Cook County is mainly urban and densely populated, containing the city of Chicago and many suburbs. However, there are still some semi-rural areas near the outskirts of the county.