Simpson County, Mississippi  Simpson County is a county located in the U.S. state of Mississippi. Its western border is formed by the Pearl River, an important transportation route in the 19th century. As of the 2010 census, the population was 27,503. The county seat is Mendenhall. The county is named for judge Josiah Simpson. Simpson County is part of the Jackson, MS Metropolitan Statistical Area. Spencer Myrick, a politician who has served in both houses of the Louisiana State Legislature, and his brother, Bill, a country music figure in Odessa, Texas, were born in Simpson County. They were reared in West Carroll Parish in northeastern Louisiana. According to the U.S. Census Bureau, the county has a total area of , of which is land and (0.2%) is water. As of the census  of 2000, there were 27,639 people, 10,076 households, and 7,385 families residing in the county. The population density was 47 people per square mile (18/km²). There were 11,307 housing units at an average density of 19 per square mile (7/km²). The racial makeup of the county was 64.39% White, 34.31% Black or African American, 0.12% Native American, 0.14% Asian, 0.01% Pacific Islander, 0.47% from other races, and 0.56% from two or more races. 1.15% of the population were Hispanic or Latino of any race. There were 10,076 households out of which 34.80% had children under the age of 18 living with them, 54.20% were married couples living together, 14.80% had a female householder with no husband present, and 26.70% were non-families. 24.00% of all households were made up of individuals and 11.10% had someone living alone who was 65 years of age or older. The average household size was 2.65 and the average family size was 3.14. In the county, the population was spread out with 27.90% under the age of 18, 9.40% from 18 to 24, 27.50% from 25 to 44, 22.10% from 45 to 64, and 13.10% who were 65 years of age or older. The median age was 35 years. For every 100 females, there were 94.40 males. For every 100 females age 18 and over, there were 90.40 males.