Clayton County, Iowa

History

The county was formed on December 21, 1837, and was named in honor of John M. Clayton, United States Senator from Delaware and later Secretary of State under President Zachary Taylor.

Geography

According to the United States Census Bureau, the county has a total area of 792.631 sqmi, of which 778.464 sqmi is land and 14.167 sqmi (0.4%) is water. It is the 5th largest county in Iowa by total area.

Adjacent counties

• Allamakee County (north)
• Crawford County, Wisconsin (northeast)
• Grant County, Wisconsin (east)
• Dubuque County (southeast)
• Delaware County (south)
• Buchanan County (southwest)
• Fayette County (west)
• Winneshiek County (northwest)

Major highways

• [[File:US 18.svg|x20px]] U.S. Highway 18
• [[File:US 52.svg|x20px]] U.S. Highway 52
• [[File:Circle sign 3.svg|x20px]] Iowa Highway 3
• [[File:Elongated circle 13.svg|x20px]] Iowa Highway 13
• [[File:Elongated circle 56.svg|x20px]] Iowa Highway 56
• [[File:Elongated circle 76.svg|x20px]] Iowa Highway 76
• [[File:Elongated circle 128.svg|x20px]] Iowa Highway 128

National protected areas

• Driftless Area National Wildlife Refuge (part)
• Effigy Mounds National Monument (part)
• Upper Mississippi River National Wildlife and Fish Refuge (part)

Geology

Clayton County is part of the Driftless Area, a region that completely missed being ice-covered during the last ice age. Streams have deeply carved valleys, while the Mississippi River has spectacular bluffs.

Demographics

|align-fn=center 1790–1960 1900–1990 1990–2000 2010–2020

2020 census

As of the 2020 census, the county had a population of 17,043 and a population density of . The median age was 46.7 years; 21.7% of residents were under the age of 18 and 24.2% were 65 years of age or older. For every 100 females there were 102.8 males, and for every 100 females age 18 and over there were 101.5 males age 18 and over.

The racial makeup of the county was 95.2% White, 0.9% Black or African American, 0.3% American Indian and Alaska Native, 0.3% Asian,

There were 7,315 households in the county, of which 24.2% had children under the age of 18 living in them. Of all households, 52.5% were married-couple households, 20.1% were households with a male householder and no spouse or partner present, and 20.7% were households with a female householder and no spouse or partner present. About 31.3% of all households were made up of individuals and 15.2% had someone living alone who was 65 years of age or older. There were 8,758 housing units, of which 7,315 were occupied, 16.5% were vacant, 77.2% of the occupied units were owner-occupied, and 22.8% were renter-occupied. The homeowner vacancy rate was 2.1% and the rental vacancy rate was 7.5%.

0.9% of residents lived in urban areas, while 99.1% lived in rural areas.

2010 census

The 2010 census recorded a population of 18,130 in the county, with a population density of . There were 8,999 housing units, of which 7,599 were occupied.

2000 census

As of the census of 2000, there were 18,678 people, about 7,500 households, and 1 family residing in the county. The population density was 24 /mi2. There were 8,620 housing units at an average density of 11 /mi2. The racial makeup of the county was 98.93% White, 0.14% Black or African American, 0.22% Native American, 0.11% Asian, 0.01% Pacific Islander, 0.19% from other races, and 0.41% from two or more races. 0.76% of the population were Hispanic or Latino of any race.

There were 7,375 households, out of which 30.90% had children under the age of 18 living with them, 59.70% were married couples living together, 6.10% had a female householder with no husband present, and 30.40% were non-families. 26.30% of all households were made up of individuals, and 13.30% had someone living alone who was 65 years of age or older. The average household size was 2.47 and the average family size was 2.98.

In the county, the population was spread out, with 25.40% under the age of 18, 6.50% from 18 to 24, 26.00% from 25 to 44, 23.60% from 45 to 64, and 18.50% who were 65 years of age or older. The median age was 40 years. For every 100 females, there were 97.60 males. For every 100 females age 18 and over, there were 95.50 males.

The median income for a household in the county was $34,068, and the median income for a family was $40,199. Males had a median income of $27,165 versus $19,644 for females. The per capita income for the county was $16,930. About 5.70% of families and 8.60% of the population were below the poverty line, including 9.60% of those under age 18 and 9.40% of those age 65 or over.

Communities

Cities

• Clayton
• Edgewood
• Elkader
• Elkport
• Farmersburg
• Garber
• Garnavillo
• Guttenberg
• Luana
• Marquette
• McGregor
• Monona
• North Buena Vista
• Osterdock
• Postville
• St. Olaf
• Strawberry Point
• Volga

Unincorporated communities

• Beulah
• Ceres
• Clayton Center
• Communia
• Eckards
• Fairview
• Froelich
• Giard
• Gunder
• Hardin
• Highland
• Littleport
• McGregor Heights
• Mederville
• Millville
• Motor
• Osborne
• Saint Sebald
• Thomasville
• Turkey River
• Updegraff
• Watson
• Wood

Townships

Clayton County is divided into these townships:

• Boardman
• Buena Vista
• Cass
• Clayton
• Cox Creek
• Elk
• Farmersburg
• Garnavillo
• Giard
• Grand Meadow
• Highland
• Jefferson
• Lodomillo
• Mallory
• Marion
• Mendon
• Millville
• Monona
• Read
• Sperry
• Volga
• Wagner

Population ranking

The population ranking of the following table is based on the 2020 census of Clayton County.

† county seat

Politics

Clayton County leaned Republican for most of its history, though starting in 1988 it saw a Democratic trend which lasted through 2012. In 2016 the county saw a heavy shift toward the Republican Party, and since then it has voted Republican by increasing margins; both 2020 and 2024 saw the strongest Republican support in the county since the landslide victory of Dwight Eisenhower in 1952.

References

References

1. "Iowa County Names and Numbers". Iowa Department of Administrative Services.
2. "Explore Census Data". [[United States Census Bureau]].
3. "Find a County". [[National Association of Counties]].
4. (2007). "Iowa: Individual County Chronologies". The [[Newberry Library]].
5. Gannett, Henry. (1905). "The Origin of Certain Place Names in the United States". [[United States Government Publishing Office.
6. "2025 County Gazetteer Files – Iowa". [[United States Census Bureau]].
7. "U.S. Census Bureau QuickFacts: Calhoun County, Iowa".
8. "County Population Totals and Components of Change: 2020-2024".
9. "U.S. Decennial Census". United States Census Bureau.
10. (2007). "Historical Census Browser". University of Virginia Library.
11. Forstall, Richard L.. (April 20, 1995). "Population of Counties by Decennial Census: 1900 to 1990". United States Census Bureau.
12. "Census 2000 PHC-T-4. Ranking Tables for Counties: 1990 and 2000". United States Census Bureau.
13. "U.S. Census Bureau QuickFacts: Clayton County, Iowa".
14. (2021). "2020 Decennial Census Demographic Profile (DP1)".
15. (2021). "2020 Decennial Census Redistricting Data (Public Law 94-171)".
16. (2023). "2020 Decennial Census Demographic and Housing Characteristics (DHC)".
17. "Population and Housing Occupancy Status: 2010 - State – County". [[United States Census Bureau]] American FactFinder.
18. "U.S. Census website". [[United States Census Bureau]].
19. "Dave Leip's Atlas of U.S. Presidential Elections".
20. Leip, David. "Dave Leip's Atlas of U.S. Presidential Elections".