Atchison County /

Atchison County is a county located in the U.S. state of Missouri. As of 2010, the population was 5,685. Its county seat is Rock Port. The county was organized in 1845 and named for David Rice Atchison, U.S. Senator from Missouri. According to the U.S. Census Bureau, the county has a total area of 547 square miles (1,416.7 km), of which 545 square miles (1,411.5 km) is land and 3 square miles (7.8 km) (0.48%) is water. As of the census of 2000, there were 6,430 people, 2,722 households, and 1,777 families residing in the county. The population density was 12 people per square mile (5/km²). There were 3,103 housing units at an average density of 6 per square mile (2/km²). The racial makeup of the county was 97.00% White, 2.05% Black or African American, 0.19% Native American, 0.14% Asian, 0.31% from other races, and 0.31% from two or more races. 0.67% of the population were Hispanic or Latino of any race. There were 2,722 households out of which 26.60% had children under the age of 18 living with them, 55.80% were married couples living together, 6.10% had a female householder with no husband present, and 34.70% were non-families. 31.50% of all households were made up of individuals