Ballwin is a southwestern suburb of St. Louis, located in St. Louis County, Missouri, United States. The population was 30,404 as of the 2010 census. Ballwin was established in 1837. The community was named for John Ball, who settled at the town site in 1804. A post office called Ballwin has been in operation since 1866.Ballwin is located at 38°35′41″N 90°32′54″W (38.594820, −90.548420). According to the United States Census Bureau, the city has a total area of 8.99 square miles (23.28 km2), all land.As of the census of 2010, there were 30,404 people, 11,874 households, and 8,631 families living in the city. The population density was 3,382.0 inhabitants per square mile (1,305.8/km2).
There were 12,435 housing units at an average density of 1,383.2 per square mile (534.1/km2). The racial makeup of the city was 89.3% White, 2.5% African American, 0.2% Native American, 5.6% Asian, 0.6% from other races, and 1.7% from two or more races. Hispanic or Latino of any race were 2.4% of the population. There were 11,874 households, of which 34.2% had children under the age of 18 living with them, 60.9% were married couples living together, 15% had a female householder with no husband present, 3.0% had a male householder with no wife present, and 27.3% were non-families. 23.1% of all households were made up of individuals, and 9.4% had someone living alone who was 65 years of age or older.
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