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Polk County, Iowa

Polk County, Iowa
Polk County Court House
Seal of Polk County, Iowa
Map of Iowa highlighting Polk County
Location in the state of Iowa
Map of the United States highlighting Iowa
Iowa's location in the U.S.
Founded 1846
Named for James K. Polk
Seat Des Moines
Largest city Des Moines
 • Total 592 sq mi (1,533 km2)
 • Land 574 sq mi (1,487 km2)
 • Water 18 sq mi (47 km2), 3.0%
 • (2010) 430,640
 • Density 751/sq mi (290/km²)
Congressional district 3rd
Time zone Central: UTC-6/-5
Website .gov.polkcountyiowawww

Polk County is a county located in the U.S. state of Iowa. As of the 2010 census, the population was 430,640,[1] making it the most populous county in Iowa. The county seat is Des Moines,[2] which is also the capital city of Iowa.

Polk County is included the Des Moines–West Des Moines, IA Metropolitan Statistical Area.[3]


  • History 1
  • Geography 2
    • Major highways 2.1
    • Adjacent counties 2.2
  • Demographics 3
    • 2010 census 3.1
    • 2000 census 3.2
  • Government and Infrastructure 4
  • Communities 5
    • Cities 5.1
    • Census-designated place 5.2
    • Unincorporated communities 5.3
    • Townships 5.4
  • See also 6
  • References 7
  • External links 8


Polk County was formed on January 13, 1846. It was named after President James K. Polk.

The first courthouse, a two-story structure, was built in 1846. Construction of a second courthouse was begun in 1858. Due to construction delays and the onset of the Civil War, the structure was not completed until 1866. The present courthouse was erected in 1906 in the Beaux Arts style. It was dedicated on October 31, 1906. In 1962, an extensive renovation was undertaken.[4]


According to the U.S. Census Bureau, the county has a total area of 592 square miles (1,530 km2), of which 574 square miles (1,490 km2) is land and 18 square miles (47 km2) (3.0%) is water.[5] The county is bisected by the Des Moines River.

Major highways

Adjacent counties


2010 census

The 2010 census recorded a population of 430,640 in the county, with a population density of 756.371/sq mi (292.037/km2). There were 182,262 housing units, of which 170,197 were occupied.[11]

2000 census

2000 Census Age Pyramid for Polk County

As of the census[12] of 2000, there were 374,601 people, 149,112 households, and 96,624 families residing in the county. The population density was 658 people per square mile (254/km²). There were 156,447 housing units at an average density of 275 per square mile (106/km²). The racial makeup of the county was 88.34% White, 4.84% Black or African American, 0.27% Native American, 2.63% Asian, 0.06% Pacific Islander, 2.22% from other races, and 1.66% from two or more races. 4.40% of the population were Hispanic or Latino of any race. 25.9% were of German, 10.6% Irish, 9.0% English and 8.4% American ancestry according to Census 2000.

There were 149,112 households out of which 32.20% had children under the age of 18 living with them, 51.00% were married couples living together, 10.30% had a female householder with no husband present, and 35.20% were non-families. 28.10% of all households were made up of individuals and 8.60% had someone living alone who was 65 years of age or older. The average household size was 2.45 and the average family size was 3.04.

Age spread: 25.70% under the age of 18, 9.40% from 18 to 24, 32.20% from 25 to 44, 21.50% from 45 to 64, and 11.10% who were 65 years of age or older. The median age was 34 years. For every 100 females there were 94.20 males. For every 100 females age 18 and over, there were 90.70 males.

The median income for a household in the county was $46,116, and the median income for a family was $56,560. Males had a median income of $37,182 versus $28,000 for females. The per capita income for the county was $23,654. About 5.30% of families and 7.90% of the population were below the poverty line, including 9.70% of those under age 18 and 6.40% of those age 65 or over.

Government and Infrastructure

The Iowa Department of Corrections Iowa Correctional Institution for Women is located in Mitchellville and in Polk County.[13]



Census-designated place

Unincorporated communities


See also


  1. ^ a b "State & County QuickFacts". United States Census Bureau. Retrieved July 20, 2014. 
  2. ^ "Find a County". National Association of Counties. Retrieved 2011-06-07. 
  3. ^  
  4. ^ Polk County
  5. ^ "US Gazetteer files: 2010, 2000, and 1990".  
  6. ^ "Annual Estimates of the Resident Population for Incorporated Places: April 1, 2010 to July 1, 2014". Retrieved June 4, 2015. 
  7. ^ "U.S. Decennial Census". United States Census Bureau. Retrieved July 20, 2014. 
  8. ^ "Historical Census Browser". University of Virginia Library. Retrieved July 20, 2014. 
  9. ^ "Population of Counties by Decennial Census: 1900 to 1990". United States Census Bureau. Retrieved July 20, 2014. 
  10. ^ "Census 2000 PHC-T-4. Ranking Tables for Counties: 1990 and 2000" (PDF). United States Census Bureau. Retrieved July 20, 2014. 
  11. ^ "Population & Housing Occupancy Status 2010".  
  12. ^ "American FactFinder".  
  13. ^ "Iowa Correctional Institution for Women." Iowa Department of Corrections. Retrieved on November 29, 2010.

External links

  • Polk County government's website
  • Historic Polk County Church: Ankeny Christian Church, Dave Clark pastor

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