Mercer County, Illinois
|Mercer County, Illinois|
Location in the state of Illinois
Illinois's location in the U.S.
|Founded||January 13, 1825|
568.69 sq mi (1,473 km²)
561.20 sq mi (1,454 km²)
7.49 sq mi (19 km²), 1.32%
31/sq mi (12/km²)
Mercer County is a county located in the U.S. state of Illinois. According to the 2010 census, it has a population of 16,434, which is a decrease of 3.1% from 16,957 in 2000. Its county seat is Aledo. It is one of the four counties that make up the Davenport-Moline-Rock Island Metropolitan Statistical Area.
Seven years after Illinois became a state, Mercer County was founded. It was formed from unorganized territory near Pike County on January 13, 1825. Although the county had been created, its government was not organized for several years; for administration purposes it was attached first to Schuyler County (until 1826), then to Peoria (until 1831), and finally to Warren County. The organization of the county government was finally completed in 1835, after a large influx of settlers following the Black Hawk War.
According to the 2010 census, the county has a total area of 568.69 square miles (1,472.9 km2), of which 561.20 square miles (1,453.5 km2) (or 98.68%) is land and 7.49 square miles (19.4 km2) (or 1.32%) is water.
Major highways 
Abington, Duncan, Eliza, Greene, Keithsburg, Mercer, Millersburg, New Boston, North Henderson, Ohio Grove, Perryton, Preemption, Richland Grove, Rivoli, Suez
Adjacent counties 
- Rock Island County - north
- Henry County - east
- Knox County - southeast
- Henderson County - south
- Warren County - south
- Des Moines County, Iowa - southwest
- Louisa County, Iowa - west
|IL Counties 1900-1990|
As of the census of 2000, there were 16,957 people, 6,624 households, and 4,915 families residing in the county. The population density was 30 people per square mile (12/km²). There were 7,109 housing units at an average density of 13 per square mile (5/km²). The racial makeup of the county was 98.37% White, 0.29% Black or African American, 0.12% Native American, 0.17% Asian, 0.01% Pacific Islander, 0.35% from other races, and 0.68% from two or more races. 1.27% of the population were Hispanic or Latino of any race. 25.4% were of German, 14.1% American, 13.0% Swedish, 12.3% English and 11.3% Irish ancestry.
There were 6,624 households out of which 32.10% had children under the age of 18 living with them, 63.5% were married couples living together, 7.2% had a female householder with no husband present, and 25.8% were non-families. 22.8% of all households were made up of individuals and 11.6% had someone living alone who was 65 years of age or older. The average household size was 2.53 and the average family size was 2.96.
In the county the population was spread out with 24.80% under the age of 18, 7.3% from 18 to 24, 26.6% from 25 to 44, 25.4% from 45 to 64, and 15.90% who were 65 years of age or older. The median age was 40 years. For every 100 females there were 96.90 males. For every 100 females age 18 and over, there were 94.20 males.
The median income for a household in the county was $40,893, and the median income for a family was $47,192. Males had a median income of $35,138 versus $22,227 for females. The per capita income for the county was $18,645. 7.8% of the population and 5.8% of families were below the poverty line. 10% of those under the age of 18 and 8.4% of those 65 and older were living below the poverty line.
Cities and towns 
- New Boston
- New Windsor
- North Henderson
- Shale City
Mercer County is divided into fifteen townships:
Climate and weather 
|Climate chart (explanation)|
In recent years, average temperatures in the county seat of Aledo have ranged from a low of 11 °F (−12 °C) in January to a high of 84 °F (29 °C) in July, although a record low of −30 °F (−34 °C) was recorded in February 1905 and a record high of 113 °F (45 °C) was recorded in July 1936. Average monthly precipitation ranged from 1.27 inches (32 mm) in January to 4.43 inches (113 mm) in June.
See also 
- "Mercer County QuickFacts". United States Census Bureau. Retrieved 2011-11-05.
- "Find a County". National Association of Counties. Retrieved 2011-06-07.
- United States Office of Management and Budget. "Update of Statistical Area Definitions and Guidance on Their Uses" (PDF). pp. 5, 36. Archived from the original on 2006-05-14. Retrieved 2006-07-21.
- Mercer County Fact Sheet, Illinois State Archives. http://www.cyberdriveillinois.com/departments/archives/irad/mercer.html
- "Census 2010 U.S. Gazetteer Files: Counties". United States Census. Retrieved 2011-11-05.
- "American FactFinder". United States Census Bureau. Retrieved 2008-01-31.
- "Monthly Averages for Aledo, Illinois". The Weather Channel. Retrieved 2011-01-27.
Further reading 
- William C. Ives, "Abraham Lincoln in Mercer County, Illinois, 1832, 1834, 1858," Journal of the Illinois State Historical Society, vol. 101 (Fall–Winter 2008), pp. 329–347.
- History of Mercer and Henderson Counties, Together with Biographical Matter, Statistics, Etc. Chicago: H.H. Hill and Company, 1882.
||Rock Island County|
|Louisa County, Iowa||Henry County|
|Des Moines County, Iowa||Henderson County and Warren County||Knox County|