Clark County, Illinois
Clark County: county in Illinois, United States
About
Clark County is a county located in the U.S. state of Illinois. As of the 2010 census, the population was 16,335 and a population density of 12 people per km². After 10 years in 2020 county had an estimated population of 15,268 inhabitants. Its county seat is Marshall. The county was created 207 years ago in 1818.
County Snapshot
Clark County at a glance
Clark County currently has 10 quality-checked populated place pages linked on MapSof, making it easier to jump from the county overview into local city pages.
Mapped populated places
10
These counts use a stricter populated-place filter so the main lists stay focused on real city and town pages.
Illinois counties
102
Open related pagesLargest city
MarshallPopulation 3,774
Top linked places
Quick Facts about Clark County
| Population | 15,268 (2020) |
| Country | United States of America |
| State | Illinois (United States) |
| Different from | Clark County, Clark County, Clark County, Clark County, Clark County, Clark County, Clark County, Clark County, Clark County, Clark County, Clark County |
| Area | 1308 km2 |
| Water as percent of area | 0.7% |
| Land as percent of area | 99.3% |
| Latitude & Longitude | 39.3336,-87.7877 |
| Named for | George Rogers Clark |
| Capital | Marshall |
| Establishment | January 01, 1819 |
| Time Zone | America/Chicago |
| Local time | 00:51:26 (18th April 2026) |
| Density | 12 Pop. per km² as of 2020 |
| Population growth | -6.99% (2010-2020) |
| Weather | 62℉ Showers And Thunderstorms Likely 7-days weather |
Geography
Clark County is located at 39°20'1"N 87°47'16"W (39.3335700, -87.7877200). It has 7 neighbors: Coles County, Crawford County, Cumberland County, Edgar County, Jasper County, Sullivan County and Vigo County.
Clark County map
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The largest city of Clark County is Marshall with a population of 3,774. Other cities include, Casey population 2,585, York population 853, Livingston population 796 and Farrington population 550. See all Clark County cities & populated places.
Clark County Populated Places
Cities, towns, neighborhoods & other populated places in Clark County.
| City Name | Population | Title |
|---|---|---|
| Marshall | 3,774 | City in Clark County, Illinois, United States |
| Casey | 2,585 | City in Illinois |
| Martinsville | 1,076 | Township in Clark County, Illinois |
| York | 853 | Town in Clark County, Wisconsin, USA |
| Livingston | 796 | Village in Illinois, US |
| Westfield | 552 | Village in Westfield Township, Clark County, Illinois |
| Farrington | 550 | Unincorporated community in Illinois |
| Orange | 517 | Unincorporated community in Illinois, United States |
| Melrose | 328 | Unincorporated community in Illinois |
| Darwin | 321 | Human settlement in Illinois, United States of America |
Weather
Showers and thunderstorms likely. Mostly cloudy. High near 62, with temperatures falling to around 54 in the afternoon. West northwest wind around 18...
7-Day ForecastOfficial website of Clark County
Official WebsiteDemographics
According to census records, the population of Clark County decreased by 6.99% in 10 years.
| Year | Population | % Change | Method |
|---|---|---|---|
| 2010 | 16,335 | - | census |
| 2011 | 16,202 | -0.82% | estimation process |
| 2012 | 16,259 | 0.35% | estimation process |
| 2013 | 16,095 | -1.02% | estimation process |
| 2014 | 16,047 | -0.3% | estimation process |
| 2015 | 15,868 | -1.13% | estimation process |
| 2016 | 15,857 | -0.07% | estimation process |
| 2017 | 15,812 | -0.28% | estimation process |
| 2018 | 15,600 | -1.36% | estimation process |
| 2019 | 15,441 | -1.03% | estimation process |
| 2020 | 15,268 | -1.13% | estimation process |
People born in Clark County (3)
People born in Clark County, including politician James Harlan, geologist and geographer Zonia Baber, politician Milton W. Mathews, .
More notable people
Other places with the same name (11)
- Clark County, Nevada county in Nevada, United States with a population of 2,315,963 people.
- Clark County, Washington county in Washington, United States with a population of 496,865 people.
- Clark County, Ohio county in Ohio, United States with a population of 133,593 people.
- Clark County, Indiana county in Indiana, United States with a population of 119,266 people.
- Clark County, Kentucky county in Kentucky, United States with a population of 36,463 people.
- Clark County, Wisconsin county in Wisconsin, United States with a population of 34,720 people.
- Clark County, Arkansas county in Arkansas, United States with a population of 22,103 people.
- Clark County, Missouri county in Missouri, United States with a population of 6,830 people.
- Clark County, South Dakota county in South Dakota, United States with a population of 3,802 people.
- Clark County, Kansas county in Kansas, United States with a population of 1,963 people.
- Clark County, Idaho county in Idaho, United States with a population of 845 people.
Illinois Other Counties (more counties)
| County Name | Population | Title |
|---|---|---|
| Cook County | 5,108,284 | County in Illinois, United States |
| Chicago | 2,677,643 | The third most populous city in the United States and the center of the Chicago metropolitan area. |
| DuPage County | 917,481 | County in Illinois, United States |
| Lake County | 693,593 | County in Oregon, United States |
| Will County | 688,726 | County in Illinois, United States |
| Kane County | 531,010 | County in southern Utah, United States |
| McHenry County | 305,888 | County in Illinois, United States |
| Winnebago County | 281,295 | County in Illinois, United States |
| Madison County | 262,635 | County in Montana, United States |
| Saint Clair County | 258,046 | The County of St. |
| Champaign County | 209,192 | County in Illinois, United States |
| Aurora | 196,383 | The second most populous city in Illinois. |
| Sangamon County | 193,882 | County in Illinois, United States |
| Peoria County | 177,652 | County in Illinois, United States of America |
| McLean County | 171,256 | County in North Dakota, United States |
| Naperville | 147,986 | The second most populous city in Illinois. |