Polk County, Iowa facts for kids

Kids Encyclopedia Facts
Polk County, Iowa
Seal of Polk County, Iowa
Map
Map of Iowa highlighting Polk County
Location in the state of Iowa
Map of the USA highlighting Iowa
Iowa's location in the U.S.
Statistics
Founded 1846
Seat Des Moines
Largest City Des Moines
Area
 - Total
 - Land
 - Water

592 sq mi (1,533 km²)
574 sq mi (1,487 km²)
18 sq mi (47 km²), 3.0%
Population
 - (2010)
 - Density

430,640
751/sq mi (290/km²)
Time zone Central: UTC-6/-5
Website: www.polkcountyiowa.gov
Named for: James K. Polk

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 Moines–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 (1,530 km2), of which 574 square miles (1,490 km2) is land and 18 square miles (47 km2) (3.0%) is water. The county is bisected by the Des Moines River.

Major highways

  • I-35 (IA).svg Interstate 35
  • I-80 (IA).svg Interstate 80
  • I-235 (IA).svg Interstate 235
  • US 6.svg U.S. Highway 6
  • US 65.svg U.S. Highway 65
  • US 69.svg U.S. Highway 69
  • Iowa 5.svg Iowa Highway 5
  • Iowa 17.svg Iowa Highway 17
  • Iowa 28.svg Iowa Highway 28
  • Iowa 141.svg Iowa Highway 141
  • Iowa 160.svg Iowa Highway 160
  • Iowa 163.svg Iowa Highway 163
  • Iowa 415.svg Iowa Highway 415

Adjacent counties

Demographics

Historical population
Census Pop.
1850 4,513
1860 11,625 157.6%
1870 27,857 139.6%
1880 42,395 52.2%
1890 65,410 54.3%
1900 82,624 26.3%
1910 110,438 33.7%
1920 154,029 39.5%
1930 172,837 12.2%
1940 195,835 13.3%
1950 226,010 15.4%
1960 266,315 17.8%
1970 286,101 7.4%
1980 303,170 6.0%
1990 327,140 7.9%
2000 374,601 14.5%
2010 430,640 15.0%
Est. 2015 467,711 8.6%
U.S. Decennial Census
1790-1960 1900-1990
1990-2000 2010-2013

2010 census

The 2010 census recorded a population of 430,640 in the county, with a population density of 756.371/sq mi (292.036/km2). There were 182,262 housing units, of which 170,197 were occupied.

2000 census

USA Polk County, Iowa age pyramid
2000 Census Age Pyramid for Polk County

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.

Communities

Cities

Census-designated place

Unincorporated communities

Townships

  • Allen
  • Beaver
  • Bloomfield
  • Camp
  • Clay
  • Crocker
  • Delaware
  • Des Moines
  • Douglas
  • Elkhart
  • Four Mile
  • Franklin
  • Jefferson
  • Lee
  • Lincoln
  • Madison
  • Saylor
  • Union
  • Walnut
  • Washington
  • Webster

Population ranking

The population ranking of the following table is based on the 2010 census of Polk County.

county seat

Rank City/Town/etc. Municipal type Population (2010 Census)
1 Des Moines City 203,433
2 West Des Moines (partially in Dallas County) City 56,609
3 Ankeny City 45,582
4 Urbandale (partially in Dallas County) City 39,463
5 Johnston City 17,278
6 Clive (partially in Dallas County) City 15,447
7 Altoona City 14,541
8 Norwalk (mostly in Warren County) City 8,945
9 Pleasant Hill City 8,785
10 Grimes (partially in Dallas County) City 8,246
11 Windsor Heights City 4,860
12 Carlisle (partially in Warren County) City 3,876
13 Bondurant City 3,860
14 Polk City City 3,418
15 Saylorville CDP 3,301
16 Mitchellville (partially in Jasper County) City 2,254
17 Granger (partially in Dallas County) City 1,244
18 Elkhart City 683
19 Runnells City 507
20 Alleman City 432
21 Sheldahl (partially in Boone and Story Counties) City 319

Polk County, Iowa Facts for Kids. Kiddle Encyclopedia.