Grundy County, Iowa

Grundy County is a county located in the U.S. state of Iowa. At the 2020 census, the population was 12,329,^[2] and was estimated to be 12,405 in 2024.^[3] The county seat and the largest city is Grundy Center.^[4] The county is named for Felix Grundy, former U.S. Attorney General.^[5]

Grundy County is included in the Waterloo–Cedar Falls metropolitan area.^[6]

Grundy County was formed on January 15, 1851, and became self-governing in 1856. It was named after Felix Grundy, a U.S. Senator and Representative from Tennessee and a former U.S. Attorney General under President Martin Van Buren.

The first courthouse was built in 1861. The wooden, two-story building contained a courtroom, but was used for other purposes, including housing the office of the sheriff, county treasurer, the judge, as well as a chamber for the jury. The cornerstone for a second courthouse was laid on November 11, 1891.^[7]

According to the United States Census Bureau, the county has a total area of 501.891 square miles (1,299.89 km²), of which 501.855 square miles (1,299.80 km²) is land and 0.036 square miles (0.093 km²) (0.01%) is water.^[8] It is the 71st largest county in Iowa by total area.^[9]

• U.S. Highway 20
• Iowa Highway 14
• Iowa Highway 57
• Iowa Highway 175

• Butler County (north)
• Black Hawk County (east)
• Tama County (southeast)
• Marshall County (southwest)
• Hardin County (west)
• Franklin County (northwest)

As of the 2020 census, the county had a population of 12,329 and a population density of 24.6/sq mi (9.5/km²).^[15] 96.97% of the population reported being of one race.^[16]

The racial makeup of the county was 96.0% White, 0.4% Black or African American, 0.1% American Indian and Alaska Native, 0.2% Asian, <0.1% Native Hawaiian and Pacific Islander, 0.3% from some other race, and 3.0% from two or more races. Hispanic or Latino residents of any race comprised 1.2% of the population.^[16]

The median age was 42.3 years. 23.8% of residents were under the age of 18 and 21.6% of residents were 65 years of age or older. For every 100 females there were 96.2 males, and for every 100 females age 18 and over there were 94.5 males age 18 and over.^[15]

There were 5,069 households in the county, of which 28.2% had children under the age of 18 living in them. Of all households, 57.4% were married-couple households, 16.3% were households with a male householder and no spouse or partner present, and 20.9% were households with a female householder and no spouse or partner present. About 27.6% of all households were made up of individuals and 14.3% had someone living alone who was 65 years of age or older.^[15]

There were 5,465 housing units, of which 7.2% were vacant. Among occupied housing units, 82.5% were owner-occupied and 17.5% were renter-occupied. The homeowner vacancy rate was 1.5% and the rental vacancy rate was 9.4%.^[15]

<0.1% of residents lived in urban areas, while 100.0% lived in rural areas.^[17]

The 2010 census recorded a population of 12,453 in the county, with a population density of 24.8/sq mi (9.6/km²). There were 5,530 housing units, of which 5,131 were occupied.^[18]

At the 2000 census, there were 12,369 people, 4,984 households and 3,583 families residing in the county. The population density was 25 inhabitants per square mile (9.7/km²). There were 5,304 housing units at an average density of 11 per square mile (4.2/km²). The racial makeup of the county was 98.97% White, 0.08% Black or African American, 0.02% Native American, 0.29% Asian, 0.15% from other races, and 0.48% from two or more races. 0.58% of the population were Hispanic or Latino of any race.

There were 4,984 households, of which 30.70% had children under the age of 18 living with them, 63.80% were married couples living together, 5.50% had a female householder with no husband present, and 28.10% were non-families. 25.50% of all households were made up of individuals, and 14.20% had someone living alone who was 65 years of age or older. The average household size was 2.45 and the average family size was 2.94.

25.20% of the population were under the age of 18, 6.30% from 18 to 24, 25.10% from 25 to 44, 24.10% from 45 to 64, and 19.30% who were 65 years of age or older. The median age was 41 years. For every 100 females, there were 95.70 males. For every 100 females age 18 and over, there were 92.10 males.

The median household income was $39,396, and the median family income was $46,627. Males had a median income of $32,006 and females $22,003. The per capita income was $19,142. About 3.30% of families and 4.60% of the population were below the poverty line, including 4.60% of those under age 18 and 5.70% of those age 65 or over.

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

† county seat

Grundy County has long been one of the most consistently Republican counties in Iowa. The county has only voted for a candidate of a different party four times since the county was founded in 1851. The first occasion was in 1912, when former Republican Theodore Roosevelt won the county as the Progressive candidate. During his two landslide victories of 1932 and 1936, Franklin D. Roosevelt became the first Democrat to win Grundy County in its history. The final time a non-Republican candidate carried the county was in 1964, when Lyndon B. Johnson won in a nationwide landslide. No Democratic candidate has ever received more than 60% of the vote in the county, and in the last twenty-one elections (beginning in 1944), the Republican obtained at least 60% of the vote in sixteen of them, and the Republicans have hit at least 65% in ten of the twenty-one elections in that span.

• National Register of Historic Places listings in Grundy County, Iowa

• County of Grundy – official website