Carroll County was formed on January 15, 1851, from sections of Pottawattamie County. It was named after Charles Carroll[3] of Carrollton, Maryland, the only Roman Catholic and longest-living signer of the Declaration of Independence. In 1855, the county government was established in Carrollton and in 1858, the first courthouse was built. In 1869, the seat was moved to Carroll City (today Carroll) which was centrally located and connected to the Chicago and North Western Transportation Company. The courthouse was destroyed in 1886 by fire. The present courthouse was erected in 1965. However the courthouse is set to go under construction in the near future.
Geography
According to the U.S. Census Bureau, the county has a total area of 570 square miles (1,500 km2), of which 569 square miles (1,470 km2) is land and 0.8 square miles (2.1 km2) (0.1%) is water.[4]
U.S. Decennial Census[6] 1790-1960[7] 1900-1990[8] 1990-2000[9] 2010-2018[10]
2020 census
The 2020 census recorded a population of 20,760 in the county, with a population density of 35.845/sq mi (13.840/km2). 97.14% of the population reported being of one race. 91.28% were non-Hispanic White, 1.26% were Black, 2.86% were Hispanic, 0.15% were Native American, 0.36% were Asian, 0.00% were Native Hawaiian or Pacific Islander and 4.08% were some other race or more than one race. There were 9,490 housing units of which 8,764 were occupied.[1]
2010 census
The 2010 census recorded a population of 20,816 in the county, with a population density of 36.58/sq mi (14.125/km2). There were 9,376 housing units, of which 8,683 were occupied.[11]
2000 census
As of the census[12] of 2000, there were 21,421 people, 8,486 households, and 5,668 families residing in the county. The population density was 38 people per square mile (15 people/km2). There were 9,019 housing units at an average density of 16 units per square mile (6.2 units/km2). The racial makeup of the county was 98.87% White, 0.18% Black or African American, 0.10% Native American, 0.34% Asian, 0.20% from other races, and 0.31% from two or more races. 0.54% of the population were Hispanic or Latino of any race.
There were 8,486 households, out of which 32.90% had children under the age of 18 living with them, 57.00% were married couples living together, 6.80% had a female householder with no husband present, and 33.20% were non-families. 29.60% of all households were made up of individuals, and 15.50% 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 3.07.
In the county, the population was spread out, with 26.90% under the age of 18, 7.40% from 18 to 24, 25.90% from 25 to 44, 21.00% from 45 to 64, and 18.70% who were 65 years of age or older. The median age was 39 years. For every 100 females there were 95.10 males. For every 100 females age 18 and over, there were 92.00 males.
The median income for a household in the county was $37,275, and the median income for a family was $47,040. Males had a median income of $30,074 versus $21,528 for females. The per capita income for the county was $18,595. About 4.50% of families and 6.50% of the population were below the poverty line, including 6.10% of those under age 18 and 8.20% of those age 65 or over.