# Clayton County, Iowa

Clayton County is a county located in the U.S. state of Iowa. As of the 2020 census, the population was 17,043. Its county seat is Elkader. The county was established in 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 U.S. Census Bureau, the county has a total area of 793 square miles (2,050 km$^2$), of which 779 square miles (2,020 km$^2$) is land and 14 square miles (36 km$^2$) (1.8%) is water. It is the fifth-largest county in Iowa by 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

* U.S. Highway 18
* U.S. Highway 52
* Iowa Highway 3
* Iowa Highway 13
* Iowa Highway 56
* Iowa Highway 76
* 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
### 2020 census

The 2020 census recorded a population of 17,043 in the county, with a population density of 21.5323/sq mi (8.31366/km$^2$). 97.51% of the population reported being of one race. 93.21% were non-Hispanic White, 0.93% were Black, 2.01% were Hispanic, 0.25% were Native American, 0.28% were Asian, 0.04% were Native Hawaiian or Pacific Islander and 3.29% were some other race or more than one race. There were 8,758 housing units, of which 7,315 were occupied.

### 2010 census

The 2010 census recorded a population of 18,130 in the county, with a population density of 23.272/sq mi (8.985/km$^2$). 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 people per square mile (9.3 people/km$^2$). There were 8,620 housing units at an average density of 11 units per square mile (4.2 units/km$^2$). 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
| Rank | City/Town/etc. | Population (2020 Census) |
| 1 | Postville (partially in Allamakee County) | 2,503 |
| 2 | Guttenberg | 1,817 |
| 3 | Monona | 1,471 |
| 4 | † Elkader | 1,209 |
| 5 | Strawberry Point | 1,155 |
| 6 | Edgewood (partially in Delaware County) | 909 |
| 7 | Garnavillo | 763 |
| 8 | McGregor | 742 |
| 9 | Marquette | 429 |
| 10 | Luana | 301 |
| 11 | Farmersburg | 271 |
| 12 | Volga | 203 |
| 13 | North Buena Vista | 109 |
| 14 | St. Olaf | 106 |
| 15 | Garber | 76 |
| 16 | Clayton | 45 |
| 17 | Osterdock | 43 |
| 18 | Elkport | 29 |

## Politics

United States presidential election results for Clayton County, Iowa :
| Year | Republican | Republican | Democratic | Democratic | Third party(ies) | Third party(ies) |
| Year | No. | % | No. | % | No. | % |
| 2024 | 6,255 | 66.54% | 3,017 | 32.10% | 128 | 1.36% |
| 2020 | 6,106 | 63.64% | 3,340 | 34.81% | 148 | 1.54% |
| 2016 | 5,317 | 58.24% | 3,237 | 35.46% | 575 | 6.30% |
| 2012 | 4,164 | 45.57% | 4,806 | 52.59% | 168 | 1.84% |
| 2008 | 3,651 | 40.61% | 5,195 | 57.79% | 144 | 1.60% |
| 2004 | 4,312 | 47.03% | 4,736 | 51.66% | 120 | 1.31% |
| 2000 | 4,034 | 47.07% | 4,238 | 49.45% | 299 | 3.49% |
| 1996 | 2,944 | 35.93% | 4,284 | 52.28% | 966 | 11.79% |
| 1992 | 3,044 | 33.12% | 3,742 | 40.72% | 2,404 | 26.16% |
| 1988 | 3,839 | 46.58% | 4,320 | 52.41% | 83 | 1.01% |
| 1984 | 5,029 | 58.80% | 3,446 | 40.29% | 78 | 0.91% |
| 1980 | 5,115 | 55.56% | 3,297 | 35.81% | 794 | 8.62% |
| 1976 | 4,826 | 54.80% | 3,804 | 43.19% | 177 | 2.01% |
| 1972 | 5,447 | 60.20% | 3,366 | 37.20% | 235 | 2.60% |
| 1968 | 5,132 | 57.81% | 3,168 | 35.68% | 578 | 6.51% |
| 1964 | 3,923 | 41.08% | 5,624 | 58.89% | 3 | 0.03% |
| 1960 | 6,441 | 58.25% | 4,612 | 41.71% | 4 | 0.04% |
| 1956 | 6,529 | 59.76% | 4,384 | 40.12% | 13 | 0.12% |
| 1952 | 7,669 | 67.22% | 3,730 | 32.70% | 9 | 0.08% |
| 1948 | 5,151 | 50.94% | 4,857 | 48.04% | 103 | 1.02% |
| 1944 | 5,855 | 57.61% | 4,259 | 41.91% | 49 | 0.48% |
| 1940 | 7,443 | 59.86% | 4,973 | 40.00% | 18 | 0.14% |
| 1936 | 5,017 | 41.00% | 6,731 | 55.01% | 488 | 3.99% |
| 1932 | 3,725 | 33.46% | 7,347 | 65.99% | 62 | 0.56% |
| 1928 | 6,774 | 61.28% | 4,231 | 38.28% | 49 | 0.44% |
| 1924 | 4,168 | 41.48% | 1,556 | 15.48% | 4,325 | 43.04% |
| 1920 | 6,747 | 77.50% | 1,808 | 20.77% | 151 | 1.73% |
| 1916 | 3,347 | 57.54% | 2,379 | 40.90% | 91 | 1.56% |
| 1912 | 1,239 | 21.14% | 2,919 | 49.80% | 1,703 | 29.06% |
| 1908 | 2,773 | 47.04% | 3,026 | 51.33% | 96 | 1.63% |
| 1904 | 3,339 | 54.59% | 2,628 | 42.96% | 150 | 2.45% |
| 1900 | 3,366 | 53.07% | 2,884 | 45.47% | 92 | 1.45% |
| 1896 | 3,302 | 52.16% | 2,910 | 45.96% | 119 | 1.88% |