Marengo, Iowa

Marengo is a city in and the county seat of Iowa County, Iowa, United States. It has served as the county seat since August 1845, even though it was not incorporated until July 1859. The population was 2,435 in the 2020 census, a decline from 2,535 in 2000.

Marengo was laid out in 1845 and platted in 1847. The city's name commemorates the Battle of Marengo, where Napoleon defeated the Austrian army.

The Iowa County Courthouse, built in 1893, is on the National Register of Historic Places.

In 1859, abolitionist John Brown led a group of escaped slaves from Missouri to Michigan. On February 20, the group stayed at the Draper B. Reynolds Farm 1.5 miles south of Marengo.

According to the United States Census Bureau, the city has a total area of 2.14 square miles (5.54 km²), of which 2.08 square miles (5.39 km²) is land and 0.06 square miles (0.16 km²) is water.

The Iowa River passes north of town.

As of the census of 2020, there were 2,435 people, 1,057 households, and 615 families residing in the city. The population density was 1,151.2 inhabitants per square mile (444.5/km²). There were 1,147 housing units at an average density of 542.3 per square mile (209.4/km²). The racial makeup of the city was 93.3% White, 0.2% Black or African American, 0.1% Native American, 0.5% Asian, 0.0% Pacific Islander, 1.1% from other races and 4.7% from two or more races. Hispanic or Latino persons of any race comprised 4.1% of the population.

Of the 1,057 households, 26.7% of which had children under the age of 18 living with them, 41.4% were married couples living together, 7.8% were cohabitating couples, 30.8% had a female householder with no spouse or partner present and 20.0% had a male householder with no spouse or partner present. 41.8% of all households were non-families. 35.1% of all households were made up of individuals, 16.8% had someone living alone who was 65 years old or older.