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Polk County, Iowa facts for kids

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Polk County
Polk County Courthouse
Polk County Courthouse
Flag of Polk County
Flag
Official seal of Polk County
Seal
Map of Iowa highlighting Polk County
Location within the U.S. state of Iowa
Map of the United States highlighting Iowa
Iowa's location within the U.S.
Country  United States
State  Iowa
Founded January 13, 1846
Named for James K. Polk
Seat Des Moines
Largest city Des Moines
Area
 • Total 592 sq mi (1,530 km2)
 • Land 574 sq mi (1,490 km2)
 • Water 18 sq mi (50 km2)  3.0%
Population
 (2020)
 • Total 492,401
 • Density 831.8/sq mi (321.14/km2)
Time zone UTC−6 (Central)
 • Summer (DST) UTC−5 (CDT)
Congressional district 3rd

Polk County is located in the U.S. state of Iowa. As of the 2020 census, the population was 492,401. It is Iowa's most populous county, and home to over 15% of the state's residents. The county seat is Des Moines, which is also the capital city of Iowa. Polk County is included in 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%
2020 492,401 14.3%
U.S. Decennial Census
1790–1960 1900–1990
1990–2000 2010–2019
PolkCountyIowaPop2020
Population of Polk County from US census data

2020 census

The 2020 census recorded a population of 492,401 in the county, with a population density of 833.5383/sq mi (321.8309/km2). 92.55% of the population reported being of one race. 66.18% were non-Hispanic White, 7.23% were Black, 9.76% were Hispanic, 0.46% were Native American, 4.98% were Asian, 0.06% were Native Hawaiian or Pacific Islander and 11.33% were some other race or more than one race. There were 210,184 housing units, of which 196,891 were occupied.

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.

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
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