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 In the United States, a state is a constituent political entity, of which there are 50. Bound together in a political union, each state holds governmental jurisdiction over a separate and defined geographic territory where it shares its so ...

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 Davenport may refer to: Places Australia *Davenport, Northern Territory, a locality *Hundred of Davenport, cadastral unit in South Australia **Davenport, South Australia, suburb of Port Augusta **District Council of Davenport, former local govern ...

- 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 The Meskwaki (sometimes spelled Mesquaki), also known by the European exonyms Fox Indians or the Fox, are a Native American people. They have been closely linked to the Sauk people of the same language family. In the Meskwaki language, th ...

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 The Sinnissippi Mounds are a Havana Hopewell culture burial mound grouping located in the city of Sterling, Illinois, United States. History The mounds are a product of the Hopewell tradition which flourished in the Sterling area around 2,000 ...

, 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 United States Census Bureau, officially the Bureau of the Census, is a principal agency of the U.S. federal statistical system, responsible for producing data about the American people and economy. The U.S. Census Bureau is part of the U ...

, 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 74 (I-74) is an Interstate Highway in the Midwestern and Southeastern United States. Its western end is at an interchange with I-80 in Davenport, Iowa; the eastern end of its Midwest segment is at an interchange with I-75 in ...

Interstate 80 Interstate 80 (I-80) is an east–west transcontinental freeway that crosses the United States from San Francisco, California, to Teaneck, New Jersey, in the New York metropolitan area. The highway was designated in 1956 as one of the ori ...

* Interstate 88 * Interstate 280 * U.S. Highway 6 * U.S. Highway 67 * U.S. Highway 150 *

Illinois Route 2 Illinois Route 2 (IL 2) is a north–south state highway in northern Illinois. It currently starts at Illinois Route 40 in Sterling, Illinois, Sterling and ends at the Wisconsin state line in South Beloit, Illinois, South Beloit, very near th ...

(formerly) *

Illinois Route 5 Illinois Route 5 (IL 5) is a four to six lane state highway in Rock Island County, Illinois, United States, that runs from U.S. Route 67 (US 67) in Rock Island to the interchange of Interstate 80 (I-80) and the toll-free portion of ...

Illinois Route 84 Illinois Route 84 (Route 84 or IL 84) is a long state highway that runs along the Mississippi River in northwestern Illinois. Illinois 84 runs from south of Green Rock, Illinois, Green Rock (now Colona, Illinois, Colona) at U.S. Route 6 (Illinoi ...

Illinois Route 92 Illinois Route 92 (IL 92 or Route 92) is an east–west state highway in northwest Illinois. It runs from the Norbert F. Beckey Bridge across the Mississippi River where it meets the eastern end of Iowa Highway 92, east to U.S. Route ...

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 110 110 may refer to: *110 (number), natural number *AD 110, a year *110 BC, a year *110 film, a cartridge-based film format used in still photography *110 (MBTA bus), Massachusetts Bay Transportation Authority bus route *110 (song), 2019 song by Capi ...

* Illinois Route 192

Transit

Quad Cities MetroLINK The Quad Cities MetroLINK, officially the Rock Island County Metropolitan Mass Transit District, provides mass transportation for the Illinois half of the Quad Cities metro area. Both Iowa cities that make up the region have their own systems, se ...

List of intercity bus stops in Illinois A list is a set of discrete items of information collected and set forth in some format for utility, entertainment, or other purposes. A list may be memorialized in any number of ways, including existing only in the mind of the list-maker, but ...

Adjacent counties

Clinton County Clinton County may refer to: *Counties named for George Clinton, first and third Governor of New York, and later the fourth Vice President of the United States: **Clinton County, New York ** Clinton County, Ohio *Counties named for DeWitt Clinton, ...

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 The Upper Mississippi River National Wildlife and Fish Refuge is a , See also * Izaak Walton League * List of National Wildlife Refuges *Trempealeau National Wildlife Refuge Trempealeau National Wildlife Refuge is a National Wildlife 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 German(s) may refer to: * Germany, the country of the Germans and German things **Germania (Roman era) * Germans, citizens of Germany, people of German ancestry, or native speakers of the German language ** For citizenship in Germany, see also Ge ...

, 14.2% were Irish, 8.7% were English, 6.8% were Swedish, and 5.2% were

American American(s) may refer to: * American, something of, from, or related to the United States of America, commonly known as the "United States" or "America" ** Americans, citizens and nationals of the United States of America ** American ancestry, p ...

. 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 Hampton may refer to: Places Australia *Hampton bioregion, an IBRA biogeographic region in Western Australia * Hampton, New South Wales *Hampton, Queensland, a town in the Toowoomba Region * Hampton, Victoria ** Hampton railway station, Melbour ...

* 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 The Rock Island Arsenal comprises 946 acres (383 ha) and is located on Arsenal Island, originally known as Rock Island, on the Mississippi River between the cities of Davenport, Iowa, and Rock Island, Illinois. It is home to the United Stat ...

Unincorporated communities

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

Townships

Rock Island County is divided into eighteen

townships A township is a form of human settlement or administrative subdivision. Its exact definition varies among countries. Although the term is occasionally associated with an urban area, this tends to be an exception to the rule. In Australia, Canad ...

: *

Blackhawk Black Hawk and Blackhawk may refer to: Animals * Common black hawk, ''Buteogallus anthracinus'' * Cuban black hawk, ''Buteogallus gundlachii'' * Great black hawk, ''Buteogallus urubitinga'' * Mangrove black hawk, ''Buteogallus (anthracinus) s ...

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 Drury may refer to: Places * Drury, New Zealand, a town * Drury, a village near Buckley, Flintshire, Wales * Drury, Kansas, United States, an unincorporated community * Drury, a village in Florida, Massachusetts, United States * Drury, Missouri, ...

* Edgington *

* 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 Rock most often refers to: * Rock (geology), a naturally occurring solid aggregate of minerals or mineraloids * Rock music, a genre of popular music Rock or Rocks may also refer to: Places United Kingdom * Rock, Caerphilly, a location in Wales ...

* Rockridge Community Unit School District 300 *

Sherrard Community Unit School District 200 Sherrard may refer to: * Sherrard (name) * Sherrard, Illinois *Sherrard, West Virginia Sherrard is an unincorporated community in Marshall County, West Virginia, United States. Sherrard is located on West Virginia Route 88, east of McMechen. ...

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