Learn About
The Commemorative
Quarter for
The Commemorative Quarter for Illinois

Time Zone: Cook County lies in the Central Time Zone (CST/CDT) and observes daylight saving time.

The community of Chicago is the Seat for Cook County.

Cook County was founded in 1831 and was created by taking area from PutnamCounty.

From the Census Estimates for 2009, <1> Cook had a population of 5,287,037 people. This is a decrease of 1.67% since the last Census (which gave a population of 5,376,741 people in 2000).

At the time of the 2000 Census, Cook represented 43.29% of the total population of Illinois, making it the state's most populous county (out of 102 counties).

The following table shows the recent changes in population. Other than 2000, the population counts have been estimated by the Census Bureau.

Since 2000
Year-to-Year Change
20105,194,675-3.39%-1.75% since 2009
20095,287,037-1.67%+0.58% since 2008
20085,256,705-2.23%+0.4% since 2007
20005,376,741The Last Census

More information can be found on the Cook County Census Page for Cook County.


Below are some of the communities located in Cook County (for more communities, please visit our Nearby Page for Cook County):

Community 2009
(2009vs. 2000)
Chicago   2,851,2682,896,0161.55% decrease  
Elgin   107,51994,48713.79% increase  
Cicero   80,10085,6166.44% decrease  
Evanston   77,85774,2394.87% increase  
Arlington Heights   73,15376,0313.79% decrease  

Websites for Cook County

Official Website:   www.co.cook.il.us/

If you know of a history or genealogy society whose interest includes Cook County, would you please send us the URL for their website? We would like to add their link to our Gazetteer. To contact us, please visit our Feedback Page.

Other Roadside Stops ...

About Illinois

Find a Community within Illinois

Footnotes ...

<1>On a yearly basis, the US Census Bureau creates an estimate of the county's population. Keep in mind that this is an estimate and not an actual count. The last physical count was the 2000 Census and the next count will be for the 2010 Census.

- Return to Citation

<2>All Quarter-dollar coin images from the United States Mint.

- Return to Citation