Webster County is a county located in the U.S. state of Missouri. As of the 2010 census, the population was 36,202. Its county seat is Marshfield. The county was organized in 1855 and named for U.S. Senator and U.S. Secretary of State Daniel Webster.
Webster County straddles the drainage divide between the Missouri and Arkansas rivers and the headwaters of the James, Niangua, Gasconade, and Pomme de Terre rivers arise in Webster County.
According to the U.S. Census Bureau, the county has a total area of 594 square miles (1,540 km), of which 593 square miles (1,540 km) is land and 1.2 square miles (3.1 km) (0.2%) is water.
As of the census of 2000, there were 31,045 people, 11,073 households, and 8,437 families residing in the county. The population density was 52 people per square mile (20/km²). There were 12,052 housing units at an average density of 20 per square mile (8/km²). The racial makeup of the county was 96.20% White, 1.16% Black or African American, 0.65% Native American, 0.26% Asian, 0.03% Pacific Islander, 0.31% from other races, and 1.39% from two or more races. Approximately 1.29% of the population were Hispanic or Latino of any race.
There were 11,073 households out of which 37.90% had children under the age of 18 living with them, 64.00% were married couples living together, 8.30% had a female householder with no husband present, and 23.80% were non-families. 20.40% of all households were made up of individuals and 9.50% had someone living alone who was 65 years of age or older. The average household size was 2.72 and the average family size was 3.14.
In the county, the population was spread out with 28.90% under the age of 18, 8.30% from 18 to 24, 29.70% from 25 to 44, 21.70% from 45 to 64, and 11.40% who were 65 years of age or older. The median age was 35 years. For every 100 females, there were 101.40 males. For every 100 females age 18 and over, there were 100.30 males.
The median income for a household in the county was $39,948, and the median income for a family was $46,941. Males had a median income of $28,168 versus $20,768 for females. The per capita income for the county was $17,948. About 9.60% of families and 14.80% of the population were below the poverty line, including 21.00% of those under age 18 and 14.10% of those age 65 or over.