Rock Island County, Illinois

	Average max. and min. temperatures in °F
	Precipitation totals in inches
	Source: The Weather Channel

Rock Island, Illinois
Climate chart (explanation)
	Average max. and min. temperatures in °F
	Precipitation totals in inches
	Source: The Weather Channel
showMetric conversion
	Average max. and min. temperatures in °C
	Precipitation totals in mm

Rock Island County
Rock Island County
U.S. county
	Rock Island County Justice Center
	Logo
	Location within the U.S. state of Illinois
	Illinois's location within the U.S.
	Coordinates: 41°28′N 90°34′W / 41.47°N 90.57°W
Country	United States
State	Illinois
Founded	1831
Named for	Rock (Arsenal) Island
Seat	Rock Island
Largest city	Moline
Area
• Total	451 sq mi (1,170 km2)
• Land	428 sq mi (1,110 km2)
• Water	24 sq mi (60 km2) 5.2%
Population (2010)
• Total	147,546
• Estimate (2019)	141,879
• Density	330/sq mi (130/km2)
Time zone	UTC−6 (Central)
• Summer (DST)	UTC−5 (CDT)
Congressional district	17th
Website	www.co.rock-island.il.us

Rock Island County is a county located in the U.S. state of Illinois, bounded on the west by the Mississippi River. According to the 2010 census, it had a population of 147,546.^[1] Its county seat is Rock Island; its largest city is neighboring Moline.^[2] Rock Island County is one of the four counties that make up the Davenport-Moline-Rock Island, IA-IL Metropolitan Statistical Area.^[3]

History[]

Rock Island County at the time of its creation in 1831

Rock Island County was formed in 1831 out of Jo Daviess County. It was named for Rock Island, an island in the Mississippi River now known as Arsenal Island.^[4] The Rock River (which the Sauk and Fox Indians called Sinnissippi meaning "rocky waters")^[5] 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 are upriver at Sterling in Whiteside County.

Geography[]

According to the U.S. Census Bureau, the county has a total area of 451 square miles (1,170 km²), of which 428 square miles (1,110 km²) is land and 24 square miles (62 km²) (5.2%) is water.^[6]

Climate and weather[]

In recent years, average temperatures in the county seat of Rock Island have ranged from a low of 13 °F (−11 °C) in January to a high of 85 °F (29 °C) in July, although a record low of −22 °F (−30 °C) was recorded in February 1996 and a record high of 103 °F (39 °C) was recorded in July 2006. Average monthly precipitation ranged from 1.28 inches (33 mm) in January to 4.75 inches (121 mm) in June.^[7]

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 110
Illinois Route 192

Adjacent counties[]

Clinton County, Iowa (north)
Whiteside County (northeast)
Henry County (southeast)
Mercer County (south)
Louisa County, Iowa (southwest)
Muscatine County, Iowa (west)
Scott County, Iowa (northwest)

National protected area[]

Upper Mississippi River National Wildlife and Fish Refuge (part)

Demographics[]

Historical population
Census	Pop.		%±
1840	2,610		—
1850	6,937		165.8%
1860	21,005		202.8%
1870	29,783		41.8%
1880	38,302		28.6%
1890	41,917		9.4%
1900	55,249		31.8%
1910	70,404		27.4%
1920	92,297		31.1%
1930	98,191		6.4%
1940	113,323		15.4%
1950	133,558		17.9%
1960	150,991		13.1%
1970	166,734		10.4%
1980	165,968		−0.5%
1990	148,723		−10.4%
2000	149,374		0.4%
2010	147,546		−1.2%
2019 (est.)	141,879	^[8]	−3.8%
U.S. Decennial Census^[9] 1790-1960^[10] 1900-1990^[11] 1990-2000^[12] 2010-2019^[1]

As of the 2010 United States Census, there were 147,546 people, 61,303 households, and 38,384 families residing in the county.^[13] The population density was 345.0 inhabitants per square mile (133.2/km²). There were 65,756 housing units at an average density of 153.8 per square mile (59.4/km²).^[6] 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.^[13] 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.^[14]

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.^[13]

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, including 19.0% of those under age 18 and 7.1% of those age 65 or over.^[15]

Economy[]

At one time Mississippi Valley Airlines had its headquarters in Quad City Airport in the county.^[16] John Deere is headquartered in Moline.^[17]

Communities[]

Cities[]

East Moline
Moline
Rock Island
Silvis

Villages[]

Census-designated places[]

Unincorporated communities[]

Townships[]

Rock Island County is divided into eighteen townships:

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 outside of four national Republican landslides. In 2016, Donald Trump managed to keep Hillary Clinton to a single-digit margin of victory, the first Republican to do so since Ronald Reagan in 1984; in 2020, Joe Biden 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.^[18]

show

Presidential election results

Footnotes[]

^ Jump up to: ^a ^b "State & County QuickFacts". United States Census Bureau. Archived from the original on June 7, 2011. Retrieved July 8, 2014.
^ "Find a County". National Association of Counties. Archived from the original on May 31, 2011. Retrieved June 7, 2011.
^ 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 (PDF) on May 14, 2006. Retrieved July 21, 2006.
^ Rock Island, the island, History: Introduction Archived January 14, 2009, at the Wayback Machine, US Army Corps of Engineers
^ "Castle Rock State Park". Illinois DNR. Archived from the original on April 1, 2007. Retrieved August 3, 2014.
^ Jump up to: ^a ^b "Population, Housing Units, Area, and Density: 2010 - County". United States Census Bureau. Archived from the original on February 12, 2020. Retrieved July 12, 2015.
^ Jump up to: ^a ^b "Monthly Averages for Rock Island, Illinois". The Weather Channel. Archived from the original on November 12, 2009. Retrieved January 27, 2011.
^ "Population and Housing Unit Estimates". Retrieved May 21, 2020.
^ "U.S. Decennial Census". United States Census Bureau. Retrieved July 8, 2014.
^ "Historical Census Browser". University of Virginia Library. Archived from the original on August 11, 2012. Retrieved July 8, 2014.
^ "Population of Counties by Decennial Census: 1900 to 1990". United States Census Bureau. Archived from the original on April 24, 2014. Retrieved July 8, 2014.
^ "Census 2000 PHC-T-4. Ranking Tables for Counties: 1990 and 2000" (PDF). United States Census Bureau. Archived (PDF) from the original on December 18, 2014. Retrieved July 8, 2014.
^ Jump up to: ^a ^b ^c "DP-1 Profile of General Population and Housing Characteristics: 2010 Demographic Profile Data". United States Census Bureau. Archived from the original on February 13, 2020. Retrieved July 12, 2015.
^ "DP02 SELECTED SOCIAL CHARACTERISTICS IN THE UNITED STATES – 2006-2010 American Community Survey 5-Year Estimates". United States Census Bureau. Archived from the original on February 13, 2020. Retrieved July 12, 2015.
^ "DP03 SELECTED ECONOMIC CHARACTERISTICS – 2006-2010 American Community Survey 5-Year Estimates". United States Census Bureau. Archived from the original on February 13, 2020. Retrieved July 12, 2015.
^ "World Airline Directory." Flight International. March 30, 1985. 98 Archived February 23, 2013, at the Wayback Machine. "Head Office: PO Box 949, Quad City Airport, Moline, Illinois 61265, USA."
^ "Deere & Company World Headquarters". Retrieved March 21, 2019.
^ https://www.rockislandcounty.org/PreviousElections/
^ Leip, David. "Dave Leip's Atlas of U.S. Presidential Elections". uselectionatlas.org. Archived from the original on March 23, 2018. Retrieved May 6, 2018.

External links[]

Coordinates: 41°28′N 90°34′W / 41.47°N 90.57°W / 41.47; -90.57

[QF-1] Jump up to: ^a ^b "State & County QuickFacts". United States Census Bureau. Archived from the original on June 7, 2011. Retrieved July 8, 2014.

[GR6-2] "Find a County". National Association of Counties. Archived from the original on May 31, 2011. Retrieved June 7, 2011.

[3] 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 (PDF) on May 14, 2006. Retrieved July 21, 2006.

[4] Rock Island, the island, History: Introduction Archived January 14, 2009, at the Wayback Machine, US Army Corps of Engineers

[5] "Castle Rock State Park". Illinois DNR. Archived from the original on April 1, 2007. Retrieved August 3, 2014.

[census-density-6] Jump up to: ^a ^b "Population, Housing Units, Area, and Density: 2010 - County". United States Census Bureau. Archived from the original on February 12, 2020. Retrieved July 12, 2015.

[weather-7] Jump up to: ^a ^b "Monthly Averages for Rock Island, Illinois". The Weather Channel. Archived from the original on November 12, 2009. Retrieved January 27, 2011.

[USCensusEst2019-8] "Population and Housing Unit Estimates". Retrieved May 21, 2020.

[9] "U.S. Decennial Census". United States Census Bureau. Retrieved July 8, 2014.

[10] "Historical Census Browser". University of Virginia Library. Archived from the original on August 11, 2012. Retrieved July 8, 2014.

[11] "Population of Counties by Decennial Census: 1900 to 1990". United States Census Bureau. Archived from the original on April 24, 2014. Retrieved July 8, 2014.

[12] "Census 2000 PHC-T-4. Ranking Tables for Counties: 1990 and 2000" (PDF). United States Census Bureau. Archived (PDF) from the original on December 18, 2014. Retrieved July 8, 2014.

[census-dp1-13] Jump up to: ^a ^b ^c "DP-1 Profile of General Population and Housing Characteristics: 2010 Demographic Profile Data". United States Census Bureau. Archived from the original on February 13, 2020. Retrieved July 12, 2015.

[census-dp2-14] "DP02 SELECTED SOCIAL CHARACTERISTICS IN THE UNITED STATES – 2006-2010 American Community Survey 5-Year Estimates". United States Census Bureau. Archived from the original on February 13, 2020. Retrieved July 12, 2015.

[census-dp3-15] "DP03 SELECTED ECONOMIC CHARACTERISTICS – 2006-2010 American Community Survey 5-Year Estimates". United States Census Bureau. Archived from the original on February 13, 2020. Retrieved July 12, 2015.

[16] "World Airline Directory." Flight International. March 30, 1985. 98 Archived February 23, 2013, at the Wayback Machine. "Head Office: PO Box 949, Quad City Airport, Moline, Illinois 61265, USA."

[17] "Deere & Company World Headquarters". Retrieved March 21, 2019.

[18] ttps://www.rockislandcounty.org/PreviousElections/

[19] Leip, David. "Dave Leip's Atlas of U.S. Presidential Elections". uselectionatlas.org. Archived from the original on March 23, 2018. Retrieved May 6, 2018.

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Year	Republican	Democratic	Third parties
2020	42.9% 28,603	55.0% 36,691	2.2% 1,464
2016	42.2% 26,998	50.5% 32,298	7.3% 4,698
2012	38.2% 24,934	60.0% 39,157	1.7% 1,126
2008	37.0% 25,364	61.5% 42,210	1.5% 1,034
2004	42.4% 29,663	57.0% 39,880	0.6% 429
2000	38.7% 25,194	58.3% 37,957	3.0% 1,944
1996	33.8% 20,626	57.1% 34,822	9.0% 5,507
1992	32.2% 23,212	51.9% 37,412	15.9% 11,415
1988	40.4% 27,412	59.2% 40,174	0.5% 315
1984	46.4% 35,121	53.1% 40,208	0.5% 343
1980	48.5% 34,788	41.9% 30,045	9.7% 6,942
1976	47.7% 34,007	50.5% 35,994	1.8% 1,260
1972	53.4% 37,548	46.3% 32,529	0.4% 253
1968	43.4% 30,404	49.2% 34,506	7.5% 5,230
1964	36.2% 23,714	63.8% 41,759	0.0% 0
1960	49.0% 32,534	50.9% 33,812	0.2% 108
1956	51.7% 31,342	48.1% 29,145	0.2% 118
1952	54.1% 32,933	45.8% 27,879	0.2% 100
1948	47.0% 22,192	52.0% 24,542	1.0% 477
1944	44.2% 23,980	55.5% 30,102	0.3% 180
1940	42.0% 25,629	57.7% 35,240	0.4% 232
1936	36.8% 19,487	61.7% 32,741	1.5% 799
1932	45.6% 21,205	53.0% 24,676	1.4% 668
1928	65.2% 27,246	34.3% 14,334	0.5% 196
1924	57.7% 20,563	10.2% 3,631	32.1% 11,453
1920	71.3% 21,908	17.0% 5,208	11.7% 3,603
1916	53.2% 16,169	35.9% 10,914	10.9% 3,327
1912	42.6% 6,506	26.1% 3,997	31.3% 4,786
1908	55.5% 8,196	32.1% 4,739	12.5% 1,846
1904	61.7% 8,152	16.3% 2,156	21.9% 2,895
1900	61.2% 8,299	35.3% 4,786	3.5% 471
1896	60.1% 7,323	38.5% 4,692	1.4% 176
1892	52.4% 5,052	41.8% 4,034	5.8% 559

show v t Municipalities and communities of Rock Island County, Illinois, United States
County seat: Rock Island
Cities	East Moline Moline Rock Island Silvis
Villages	Andalusia Carbon Cliff Coal Valley‡ Cordova Hampton Hillsdale Milan Oak Grove Port Byron Rapids City Reynolds‡
Townships	Andalusia Blackhawk Bowling Buffalo Prairie Canoe Creek Coal Valley Coe Cordova Drury Edgington Hampton Moline Port Byron Rock Island Rural South Moline South Rock Island Zuma
CDPs	Barstow Buffalo Prairie Campbell's Island Coyne Center Edgington Joslin Illinois City Rock Island Arsenal Taylor Ridge
Footnotes	‡This populated place also has portions in an adjacent county or counties
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show v t Quad Cities and surrounding metropolitan area of Iowa and Illinois
Iowa	Scott County Muscatine County Clinton County Davenport Bettendorf Blue Grass Buffalo Dixon Donahue Eldridge Le Claire Long Grove Maysville McCausland New Liberty Panorama Park Park View Pleasant Valley Township Princeton Riverdale
Illinois	Henry County Mercer County Rock Island County Moline Rock Island East Moline Aledo Andalusia Annawan Barstow Bishop Hill Buffalo Prairie Cambridge Carbon Cliff Cleveland Coal Valley Colona Coyne Center Dayton Edgington Galva Geneseo Green River Hampton Hillsdale Hooppole Kewanee Illinois City Matherville Milan North Henderson Nekoma Oak Grove Ophiem Orion Osco Port Byron Reynolds Sherrard Silvis Swedona Woodhull
Attractions	American Pickers Ballet Quad Cities Credit Island Bix 7 Road Race Bix Beiderbecke Memorial Jazz Festival Davenport Skybridge Downtown Davenport Festival of Trees Figge Art Museum Iowa 80 Rhythm City Casino Resort John Deere World Headquarters John Deere Classic Jumer's Casino & Hotel Lock and Dam No. 14 Lock and Dam No. 15 Mississippi River Modern Woodmen Park Moline station Niabi Zoo NorthPark Mall Putnam Museum Quad Cities Waterfront Convention Center Quad City Air Show Quad City Botanical Center Quad City Downs Quad Cities International Airport Quad City-style pizza Quad City Symphony Orchestra River Music Experience RiverCenter Rock Island Arsenal SouthPark Mall TaxSlayer Center The Freight House TPC at Deere Run Village of East Davenport Walnut Grove Pioneer Village
Colleges	Augustana College Black Hawk College Kaplan University Palmer College of Chiropractic St. Ambrose University Scott Community College Western Illinois University-Quad Cities
Historical Places	Illinois Henry County Mercer County Rock Island County Iowa Scott County Davenport

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