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.[3] It was named for General Henry Dodge.[4]
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.[5]
Geography
According to the U.S. Census Bureau, the county has a total area of 437 square miles (1,130 km2), of which 434 square miles (1,120 km2) is land and 2.2 square miles (5.7 km2) (0.5%) is water.[6]
U.S. Decennial Census[8] 1790-1960[9] 1900-1990[10] 1990-2000[11] 2010-2018[12]
2020 census
The 2020 census recorded a population of 20,482 in the county, with a population density of 46.9453/sq mi (18.1257/km2). 95.23% of the population reported being of one race. There were 8,398 housing units, of which 7,746 were occupied.[1]
The 2010 census recorded a population of 20,145 in the county, with a population density of 47.4625/sq mi (18.3254/km2). There were 8,280 housing units, of which 7,666 were occupied.[14]
2000 census
As of the census[15] 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 (18 people/km2). There were 8,246 housing units at an average density of 19 units per square mile (7.3 units/km2). 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 couples living 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.
Henry County is one of the most Republican counties in Iowa. It has backed Democratic Party candidates in only five elections for president from 1880 to the present.
United States presidential election results for Henry County, Iowa[16]