Polk County is a county in the U.S. state of Iowa. As of the 2010 census, the population was 430,640, making it Iowa's most populous county. The county seat is Des Moines, which is also the capital city of Iowa.
Polk County is included the Des Moinesâ€"West Des Moines, IA Metropolitan Statistical Area.
History
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.
Geography
According to the U.S. Census Bureau, the county has a total area of 592 square miles (1,530Â km2), of which 574 square miles (1,490Â km2) is land and 18 square miles (47Â km2) (3.0%) is water. The county is bisected by the Des Moines River.
Major highways
Adjacent counties
- Boone County (northwest)
- Story County (north)
- Jasper County (east)
- Marion County (southeast)
- Warren County (south)
- Madison County (southwest)
- Dallas County (west)
Demographics
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.
2000 census
As of the census 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.
Communities
Cities
Census-designated place
- Saylorville
Unincorporated communities
- Avon
- Berwick
- Enterprise
- Farrar
Townships
Population ranking
The population ranking of the following table is based on the 2010 census of Polk County.
†county seat
See also
- Polk County Courthouse
- Iowa State Capitol
- Terrace Hill also known as Hubbell Mansion, Benjamin F. Allen House, or the Iowa Governor's Mansion.
- National Register of Historic Places listings in Polk County, Iowa
References
External links
- Polk County government's website
