Henry County was formed on December 7, 1836 under the jurisdiction of Wisconsin Territory, and became a part of Iowa Territory when the Iowa Territory was formed on July 4, 1838. It was named for General Henry Dodge. The county's first courthouse was built in 1839–1840. A larger courthouse was built in 1871, and the present courthouse was raised in the twentieth century, being placed into service on August 4, 1914.
Geography
According to the U.S. Census Bureau, the county has a total area of, of which is land and is water.
The 2010 census recorded a population of 20,145 in the county, with a population density of. There were 8,280 housing units, of which 7,666 were occupied.
2000 census
As of the census of 2000, there were 20,336 people, 7,626 households, and 5,269 families residing in the county. The population density was 47 people per square mile. There were 8,246 housing units at an average density of 19 per square mile. The racial makeup of the county was 94.78% White, 1.49% Black or African American, 0.24% Native American, 1.88% Asian, 0.02% Pacific Islander, 0.52% from other races, and 1.07% from two or more races. 1.26% of the population were Hispanic or Latino of any race. There were 7,626 households out of which 32.80% had children under the age of 18 living with them, 57.70% were married couplesliving together, 8.20% had a female householder with no husband present, and 30.90% were non-families. 26.80% of all households were made up of individuals and 12.20% had someone living alone who was 65 years of age or older. The average household size was 2.46 and the average family size was 2.98. In the county, the population was spread out with 24.70% under the age of 18, 9.00% from 18 to 24, 29.20% from 25 to 44, 22.50% from 45 to 64, and 14.70% who were 65 years of age or older. The median age was 37 years. For every 100 females there were 102.50 males. For every 100 females age 18 and over, there were 102.80 males. The median income for a household in the county was $39,087, and the median income for a family was $46,985. Males had a median income of $31,801 versus $23,075 for females. The per capita income for the county was $18,192. About 6.70% of families and 8.80% of the population were below the poverty line, including 10.30% of those under age 18 and 9.30% of those age 65 or over.
The population ranking of the following table is based on the 2010 census of Henry County. †county seat
Rank
City/Town/etc.
Municipal type
Population
1
†Mount Pleasant
City
8,668
2
New London
City
1,897
3
Winfield
City
1,134
4
Wayland
City
966
5
Salem
City
383
6
Olds
City
229
7
Hillsboro
City
180
8
Rome
City
117
9
Westwood
City
112
10
Mount Union
City
107
11
Coppock
City
47
Politics
Henry County is one of the most Republican counties in Iowa. It has backed Democratic Party candidates in only five elections for president from 1896 to the present.
