Grain Valley was founded in the 1870s. The city was named for the general character of the grain-producing region. A post office called Grain Valley has been in operation since 1879.
Geography
Grain Valley is located at . According to the United States Census Bureau, the city has a total area of, of which is land and is water.
Demographics
At the 2010 census there were 12,854 people in 4,566 households, including 3,395 families, in the city. The population density was. There were 4,867 housing units at an average density of. The racial makeup of the city was 92.6% White, 2.5% African American, 0.6% Native American, 0.6% Asian, 0.1% Pacific Islander, 1.2% from other races, and 2.3% from two or more races. Hispanic or Latino of any race were 4.9%. Of the 4,566 households 47.4% had children under the age of 18 living with them, 56.0% were married couplesliving together, 13.1% had a female householder with no husband present, 5.3% had a male householder with no wife present, and 25.6% were non-families. 19.1% of households were one person and 5.6% were one person aged 65 or older. The average household size was 2.81 and the average family size was 3.22. The median age was 30.5 years. 32.1% of residents were under the age of 18; 7.5% were between the ages of 18 and 24; 35.2% were from 25 to 44; 18.3% were from 45 to 64; and 6.8% were 65 or older. The gender makeup of the city was 48.9% male and 51.1% female.
At the 2000 census there were 5,160 people. The population density was 1,075.0 people per square mile. There were 2,022 housing units at an average density of 421.2 per square mile. The racial makeup of the city was 96.43% White, 0.56% African American, 0.48% Asian, 0.39% Native American, 0.16% Pacific Islander, 0.43% from other races, and 1.55% from two or more races. Hispanic or Latino of any race were 2.48%. Of the 1,921 households 44.9% had children under the age of 18 living with them, 61.2% were married couples living together, 9.8% had a female householder with no husband present, and 24.9% were non-families. 20.4% of households were one person and 6.6% were one person aged 65 or older. The average household size was 2.69 and the average family size was 3.11. The age distribution was 31.0% under the age of 18, 9.3% from 18 to 24, 39.0% from 25 to 44, 14.7% from 45 to 64, and 6.0% 65 or older. The median age was 29 years. For every 100 females, there were 99.6 males. For every 100 females age 18 and over, there were 92.4 males. The median household income was $50,118 and the median family income was $57,240. Males had a median income of $37,436 versus $27,961 for females. The per capita income for the city was $20,265. About 3.9% of families and 4.4% of the population were below the poverty line, including 6.2% of those under age 18 and 8.8% of those age 65 or over.
