Rock Island County is a

county A county () is a geographic region of a country used for administrative or other purposesL. Brookes (ed.) '' Chambers Dictionary''. Edinburgh: Chambers Harrap Publishers Ltd, 2005. in some nations. The term is derived from the Old French denoti ...

located in the U.S. state of

Illinois Illinois ( ) is a U.S. state, state in the Midwestern United States, Midwestern United States. It borders on Lake Michigan to its northeast, the Mississippi River to its west, and the Wabash River, Wabash and Ohio River, Ohio rivers to its ...

, bounded on the west by the

Mississippi River The Mississippi River is the main stem, primary river of the largest drainage basin in the United States. It is the second-longest river in the United States, behind only the Missouri River, Missouri. From its traditional source of Lake Ita ...

. According to the 2020 census, it had a population of 144,672. Its

county seat A county seat is an administrative center, seat of government, or capital city of a county or parish (administrative division), civil parish. The term is in use in five countries: Canada, China, Hungary, Romania, and the United States. An equiva ...

is Rock Island; its largest city is neighboring Moline. Rock Island County is one of the four counties that make up the Davenport- Moline-Rock Island, IA-IL Metropolitan Statistical Area.

History

Rock Island County was formed in 1831 out of Jo Daviess County. It was named for Rock Island, an island in the

now known as Arsenal Island. The Rock River (which the Sauk and Meskwaki peoples called Sinnissippi, meaning "rocky waters") flows from Whiteside County and points further east and north and joins the Mississippi River at Rock Island. The Sinnissippi Mounds, dating from the Hopewell period and on the

National Register of Historic Places The National Register of Historic Places (NRHP) is the Federal government of the United States, United States federal government's official United States National Register of Historic Places listings, list of sites, buildings, structures, Hist ...

are upriver at Sterling in Whiteside County.

Geography

According to the U.S. Census Bureau, the county has a total area of , of which is land and (5.2%) is water.

Climate and weather

In recent years, average temperatures in the county seat of Rock Island have ranged from a low of in January to a high of in July, although a record low of was recorded in February 1996 and a record high of was recorded in July 2006. Average monthly precipitation ranged from in January to in June.

Major highways

* Interstate 74 * Interstate 80 * Interstate 88 * Interstate 280 * U.S. Highway 6 * U.S. Highway 67 * U.S. Highway 150 * Illinois Route 2 (formerly) * Illinois Route 5 * Illinois Route 84 * Illinois Route 92 *

Illinois Route 94 Illinois Route 94 is a north–south state highway in western Illinois. It runs from U.S. Route 24 (US 24) just east of Camp Point to U.S. Route 67 just south of Oak Grove, just south of the Quad Cities area. This is a distance of . ...

* Illinois Route 110 * Illinois Route 192

Transit

* Quad Cities MetroLINK * List of intercity bus stops in Illinois

Adjacent counties

* Clinton County,

Iowa Iowa ( ) is a U.S. state, state in the upper Midwestern United States, Midwestern region of the United States. It borders the Mississippi River to the east and the Missouri River and Big Sioux River to the west; Wisconsin to the northeast, Ill ...

(north) * Whiteside County (northeast) * Henry County (southeast) * Mercer County (south) * Louisa County,

(southwest) * Muscatine County,

(west) * Scott County,

(northwest)

National protected area

* Upper Mississippi River National Wildlife and Fish Refuge (part)

Demographics

As of the 2010 United States census, there were 147,546 people, 61,303 households, and 38,384 families residing in the county. The population density was . There were 65,756 housing units at an average density of . The racial makeup of the county was 81.6% white, 9.0% black or African American, 1.6% Asian, 0.3% American Indian, 4.4% from other races, and 3.0% from two or more races. Those of Hispanic or Latino origin made up 11.6% of the population. In terms of ancestry, 25.9% were German, 14.2% were Irish, 8.7% were English, 6.8% were Swedish, and 5.2% were American. Of the 61,303 households, 29.0% had children under the age of 18 living with them, 45.3% were married couples living together, 12.7% had a female householder with no husband present, 37.4% were non-families, and 31.6% of all households were made up of individuals. The average household size was 2.34 and the average family size was 2.93. The median age was 40.0 years. The median income for a household in the county was $46,226 and the median income for a family was $58,962. Males had a median income of $42,548 versus $31,917 for females. The per capita income for the county was $25,071. About 8.7% of families and 12.3% of the population were below the

poverty line The poverty threshold, poverty limit, poverty line, or breadline is the minimum level of income deemed adequate in a particular country. The poverty line is usually calculated by estimating the total cost of one year's worth of necessities for ...

, including 19.0% of those under age 18 and 7.1% of those age 65 or over.

Economy

At one time Mississippi Valley Airlines had its headquarters in Quad City Airport in the county.

John Deere Deere & Company, Trade name, doing business as John Deere (), is an American corporation that manufactures agricultural machinery, heavy equipment, forestry machinery, diesel engines, drivetrains (axles, Transmission (mechanical device), transmi ...

is headquartered in Moline.

Communities

Cities

* East Moline * Moline * Rock Island * Silvis

Villages

Andalusia Andalusia ( , ; , ) is the southernmost autonomous communities of Spain, autonomous community in Peninsular Spain, located in the south of the Iberian Peninsula, in southwestern Europe. It is the most populous and the second-largest autonomou ...

* Carbon Cliff * Coal Valley (part) * Cordova * Hampton * Hillsdale *

Milan Milan ( , , ; ) is a city in northern Italy, regional capital of Lombardy, the largest city in Italy by urban area and the List of cities in Italy, second-most-populous city proper in Italy after Rome. The city proper has a population of nea ...

* Oak Grove * Port Byron * Rapids City * Reynolds (part)

Census-designated places

* Coyne Center * Rock Island Arsenal

Unincorporated communities

* Barstow * Buffalo Prairie * Campbell's Island * Edgington * Illinois City * Joslin * Taylor Ridge

Townships

Rock Island County is divided into eighteen townships: *

* Blackhawk *

Bowling Bowling is a Throwing sports#Target sports, target sport and recreational activity in which a player rolls a bowling ball, ball toward Bowling pin, pins (in pin bowling) or another target (in target bowling). Most references to ''bowling'' are ...

* Buffalo Prairie * Canoe Creek * Coal Valley * Coe * Cordova * Drury * Edgington * Hampton * Moline * Port Byron * Rock Island *

Rural In general, a rural area or a countryside is a geographic area that is located outside towns and cities. Typical rural areas have a low population density and small settlements. Agricultural areas and areas with forestry are typically desc ...

* South Moline * South Rock Island * Zuma

Forts

* Fort Armstrong

Politics

Before 1932, Rock Island County was a Republican stronghold in presidential elections, backing the party's candidate in every election from 1892 to 1928. From 1932 on, it has consistently backed Democratic Party presidential candidates, except for the national Republican landslides of 1952, 1956, 1972, and 1980. In 2016,

Donald Trump Donald John Trump (born June 14, 1946) is an American politician, media personality, and businessman who is the 47th president of the United States. A member of the Republican Party (United States), Republican Party, he served as the 45 ...

managed to keep

Hillary Clinton Hillary Diane Rodham Clinton ( Rodham; born October 26, 1947) is an American politician, lawyer and diplomat. She was the 67th United States secretary of state in the administration of Barack Obama from 2009 to 2013, a U.S. senator represent ...

to a single-digit margin of victory, the first Republican to do so since

Ronald Reagan Ronald Wilson Reagan (February 6, 1911 – June 5, 2004) was an American politician and actor who served as the 40th president of the United States from 1981 to 1989. He was a member of the Republican Party (United States), Republican Party a ...

in 1984; in 2020,

Joe Biden Joseph Robinette Biden Jr. (born November 20, 1942) is an American politician who was the 46th president of the United States from 2021 to 2025. A member of the Democratic Party (United States), Democratic Party, he served as the 47th vice p ...

increased the Democratic margin from 8.3% to 12.1%. Due to the dominance of the Democratic Party in county politics, Rock Island County remains one of the most Democratic counties outside of the Chicago area in Illinois. Since 2010 the Republican Party began making inroads in county politics, gaining a few seats on the Democratic-dominated county board; however, since 2018, the Republican Party influence on the board has begun to decrease as the county resumed heavy Democratic voting.

Education

K-12 school districts include:
Text list
/ref> * Erie Community Unit School District 1 * Mercer County School District 404 * Moline-Coal Valley School District 40 * Orion Community Unit School District 223 * Riverdale Community Unit School District 100 * Rock Island-Milan School District 41 * Rockridge Community Unit School District 300 * Sherrard Community Unit School District 200 There is one secondary school district: United Township High School District 30. Elementary school districts include: * Carbon Cliff-Barstow School District 36 * East Moline School District 37 * Hampton School District 29 * Silvis School District 34

Footnotes

External links

Official county website

Rock Island County Historical Society
{{Coord, 41.47, -90.57, display=title, type:adm2nd_region:US-IL_source:UScensus1990 Illinois counties 1831 establishments in Illinois Populated places established in 1831 Quad Cities Illinois counties on the Mississippi River