Union is a city in and the county seat of Franklin County, Missouri, United States. It is located on the Bourbeuse River, 50 miles (80 km) southwest of St. Louis. The population was 10,204 at the 2010 census, with the city showing the highest growth rate (32%) in Franklin County over the previous decade.
The city is located on the northwest side of the Bourbeuse River. US Route 50 passes through the city and I-44 is approximately five miles to the east. Washington, on the Missouri River, is seven miles to the north on Missouri Route 47.
According to the United States Census Bureau, the city has a total area of 9.16 square miles (23.72 km), all land.
As of the census of 2010, there were 10,204 people, 3,902 households, and 2,612 families residing in the city. The population density was 1,114.0 inhabitants per square mile (430.1/km). There were 4,226 housing units at an average density of 461.4 per square mile (178.1/km). The racial makeup of the city was 95.7% White, 1.1% African American, 0.6% Native American, 0.4% Asian, 0.5% from other races, and 1.6% from two or more races. Hispanic or Latino of any race were 1.4% of the population.
There were 3,902 households of which 39.1% had children under the age of 18 living with them, 47.7% were married couples living together, 13.1% had a female householder with no husband present, 6.1% had a male householder with no wife present, and 33.1% were non-families. 27.1% of all households were made up of individuals and 10.8% had someone living alone who was 65 years of age or older. The average household size was 2.59 and the average family size was 3.14.
The median age in the city was 31.9 years. 28.2% of residents were under the age of 18; 9.9% were between the ages of 18 and 24; 29.1% were from 25 to 44; 21.4% were from 45 to 64; and 11.5% were 65 years of age or older. The gender makeup of the city was 48.3% male and 51.7% female.
As of the 2000 United States Census, there were 7,757 people, 2,940 households, and 2,002 families residing in the city. The population density was 959.9 people per square mile (370.7/km²). There were 3,133 housing units at an average density of 387.7 per square mile (149.7/km²). The racial makeup of the city was 96.44% White, 1.43% African American, 0.30% Native American, 0.17% Asian, 0.23% from other races, and 1.43% from two or more races. Hispanic or Latino of any race were 0.99% of the population.
There were 2,940 households out of which 35.7% had children under the age of 18 living with them, 52.7% were married couples living together, 11.5% had a female householder with no husband present, and 31.9% were non-families. 26.8% of all households were made up of individuals and 11.1% had someone living alone who was 65 years of age or older. The average household size was 2.56 and the average family size was 3.10.
The median income for a household in the city was $39,596, and the median income for a family was $44,474. Males had a median income of $31,852 versus $22,924 for females. The per capita income for the city was $16,885. About 4.2% of families and 7.2% of the population were below the poverty line, including 4.8% of those under age 18 and 11.2% of those age 65 or over.