Rock County
Rock County Courthouse
Rock County Courthouse
Official seal of Rock County
Map of Wisconsin highlighting Rock County
Location within the U.S. state of Wisconsin
Map of the United States highlighting Wisconsin
Wisconsin's location within the U.S.
Coordinates: 42°40′N 89°04′W / 42.67°N 89.07°W / 42.67; -89.07
Country United States
State Wisconsin
Founded1839
Named forRock River
SeatJanesville
Largest cityJanesville
Area
 • Total726 sq mi (1,880 km2)
 • Land718 sq mi (1,860 km2)
 • Water8.0 sq mi (21 km2)  1.1%%
Population
 • Total163,687
 • Density230/sq mi (87/km2)
Time zoneUTC−6 (Central)
 • Summer (DST)UTC−5 (CDT)
Congressional districts1st, 2nd
Websitewww.co.rock.wi.us

Rock County is a county in the U.S. state of Wisconsin. As of the 2020 census, the population was 163,687.[1] Its county seat is Janesville.[2] Rock County comprises the Janesville-Beloit, WI Metropolitan Statistical Area and is included in the Madison-Janesville-Beloit, WI Combined Statistical Area.

History

Rock County was created in 1836 as a territorial county on December 7, 1836, from Milwaukee County and fully organized February 19, 1839.[3] The county is named for the Rock River, which bisects the county from north to south.[4]

Geography

According to the U.S. Census Bureau, the county has a total area of 726 square miles (1,880 km2), of which 718 square miles (1,860 km2) is land and 8.0 square miles (21 km2) (1.1%) is water.[5]

Cook Memorial Arboretum, a natural area with birding and nature trails, is located northwest of Janesville. It is owned by the Janesville School District.[6]

Transportation

Major highways

Railroads

Buses

Airport

Southern Wisconsin Regional Airport (KJVL) serves Rock County and the surrounding communities.

Adjacent counties

Demographics

Historical population
Census Pop.
18401,701
185020,7501,119.9%
186036,69076.8%
187039,0306.4%
188038,823−0.5%
189043,22011.3%
190051,20318.5%
191055,5388.5%
192066,15019.1%
193074,20612.2%
194080,1738.0%
195092,77815.7%
1960113,91322.8%
1970131,97015.9%
1980139,4205.6%
1990139,5100.1%
2000152,3079.2%
2010160,3315.3%
2020163,6872.1%
U.S. Decennial Census[7]
1790–1960[8] 1900–1990[9]
1990–2000[10] 2010[11] 2020[1]

As of the census of 2020,[1] the population was 163,687. The population density was 227.9 inhabitants per square mile (88.0/km2). There were 70,068 housing units at an average density of 97.6 per square mile (37.7/km2). The racial makeup of the county was 81.3% White, 5.1% Black or African American, 1.3% Asian, 0.5% Native American, 4.6% from other races, and 7.2% from two or more races. Ethnically, the population was 9.7% Hispanic or Latino of any race.

2000 Census Age Pyramid for Rock County
2000 Census Age Pyramid for Rock County

As of the census[12] of 2010, there were 160,331 people residing in the county.

As of the census[12] of 2000, were 152,307 people, 58,617 households, and 40,387 families residing in the county. The population density was 211 people per square mile (82/km2). there were 62,187 housing units at an average density of 86 per square mile (33/km2). The racial makeup of the county was 91.01% white, 4.63% black or African American, 0.28% Native American, 0.78% Asian, 0.04% Pacific Islander, 1.77% from other races, and 1.50% from two or more races. 3.91% of the population were Hispanic or Latino of any race. 32.8% were of German, 13.0% Norwegian, 10.1% Irish, 7.5% English and 5.5% American ancestry.

There were 58,617 households, out of which 33.60% had children under the age of 18 living with them, 53.50% were married couples living together, 10.90% had a female householder with no husband present, and 31.10% were non-families. 25.10% of all households were made up of individuals, and 9.70% had someone living alone who was 65 years of age or older. The average household size was 2.54 and the average family size was 3.03.

In the county, the population was spread out, with 26.50% under the age of 18, 8.60% from 18 to 24, 29.80% from 25 to 44, 22.30% from 45 to 64, and 12.70% who were 65 years of age or older. The median age was 36 years. For every 100 females there were 97.00 males. For every 100 females age 18 and over, there were 94.10 males.

Communities

Cities

Villages

Towns

Census-designated place

Unincorporated communities

Ghost towns/neighborhoods

Politics

Hillary Clinton carried the county in 2016, but it was the smallest margin of victory since Michael Dukakis in 1988.

United States presidential election results for Rock County, Wisconsin[13]
Year Republican Democratic Third party
No.  % No.  % No.  %
2020 37,138 43.51% 46,658 54.66% 1,564 1.83%
2016 31,493 41.40% 39,339 51.71% 5,242 6.89%
2012 30,517 37.82% 49,219 61.00% 954 1.18%
2008 27,364 34.56% 50,529 63.82% 1,276 1.61%
2004 33,151 41.19% 46,598 57.90% 730 0.91%
2000 27,467 39.01% 40,472 57.49% 2,465 3.50%
1996 20,096 33.32% 32,450 53.80% 7,774 12.89%
1992 21,942 31.79% 31,154 45.13% 15,929 23.08%
1988 28,178 48.43% 29,576 50.83% 434 0.75%
1984 32,491 54.76% 26,433 44.55% 410 0.69%
1980 30,960 50.60% 24,740 40.44% 5,482 8.96%
1976 28,325 49.04% 28,048 48.56% 1,389 2.40%
1972 30,361 58.03% 21,033 40.20% 925 1.77%
1968 25,229 50.97% 20,567 41.56% 3,697 7.47%
1964 20,372 41.85% 28,257 58.04% 55 0.11%
1960 29,675 60.63% 19,194 39.22% 76 0.16%
1956 28,980 67.42% 13,834 32.18% 173 0.40%
1952 27,837 64.64% 15,183 35.26% 45 0.10%
1948 17,068 50.66% 16,150 47.93% 474 1.41%
1944 18,477 52.23% 16,766 47.39% 133 0.38%
1940 20,141 53.15% 17,543 46.29% 214 0.56%
1936 14,693 43.56% 17,991 53.34% 1,045 3.10%
1932 16,825 56.07% 12,612 42.03% 571 1.90%
1928 21,497 70.75% 8,726 28.72% 161 0.53%
1924 14,815 60.92% 1,453 5.97% 8,052 33.11%
1920 16,152 83.53% 2,447 12.65% 738 3.82%
1916 7,011 61.09% 4,015 34.98% 451 3.93%
1912 4,276 43.21% 3,032 30.64% 2,587 26.14%
1908 7,839 66.81% 3,227 27.50% 668 5.69%
1904 7,972 71.65% 2,348 21.10% 807 7.25%
1900 8,249 69.97% 3,094 26.24% 447 3.79%
1896 8,282 67.46% 3,655 29.77% 340 2.77%
1892 6,052 55.24% 4,231 38.62% 673 6.14%


Tree cities

See also

References

  1. ^ a b c d "2020 Decennial Census: Rock County, Wisconsin". data.census.gov. U.S. Census Bureau. Retrieved July 3, 2022.
  2. ^ "Find a County". National Association of Counties. Retrieved June 7, 2011.
  3. ^ "Wisconsin: Individual County Chronologies". Wisconsin Atlas of Historical County Boundaries. The Newberry Library. 2007. Archived from the original on April 14, 2017. Retrieved August 15, 2015.
  4. ^ "Rock County, origin of place name" Dictionary of Wisconsin History.
  5. ^ "2010 Census Gazetteer Files". United States Census Bureau. August 22, 2012. Retrieved August 8, 2015.
  6. ^ Great Wisconsin Birding & Nature Trail. Cook Memorial Arboretum.
  7. ^ "U.S. Decennial Census". United States Census Bureau. Retrieved August 8, 2015.
  8. ^ "Historical Census Browser". University of Virginia Library. Retrieved August 8, 2015.
  9. ^ Forstall, Richard L., ed. (March 27, 1995). "Population of Counties by Decennial Census: 1900 to 1990". United States Census Bureau. Retrieved August 8, 2015.
  10. ^ "Census 2000 PHC-T-4. Ranking Tables for Counties: 1990 and 2000" (PDF). United States Census Bureau. April 2, 2001. Retrieved August 8, 2015.
  11. ^ "State & County QuickFacts". United States Census Bureau. Archived from the original on February 27, 2016. Retrieved January 23, 2014.
  12. ^ a b "U.S. Census website". United States Census Bureau. Retrieved May 14, 2011.
  13. ^ Leip, David. "Dave Leip's Atlas of U.S. Presidential Elections". uselectionatlas.org. Retrieved November 11, 2020.

Further reading

Coordinates: 42°40′N 89°04′W / 42.67°N 89.07°W / 42.67; -89.07