Demographics 2020 census Note: the US Census treats Hispanic/Latino as an ethnic category. This table excludes Latinos from the racial categories and assigns them to a separate category. Hispanics/Latinos can be of any race. As of the 2020 United States census, there were 17,968 people, 6,778 households, and 4,232 families residing in the county. 2000 census As of the census of 2000, there were 18,733 people, 6,629 households, and 4,680 families residing in the county. The population density was 27 people per square mile (10/km2). There were 7,836 housing units at an average density of 11 per square mile (4/km2). The racial makeup of the county was 57.49% Caucasian, 40.30% Black or African American, 0.32% Native American, 0.32% Asian, 0.02% Pacific Islander, 0.51% from other races, and 1.04% from two or more races. 3.20% of the population were Hispanic or Latino of any race. There were 6,629 households, out of which 31.90% had children under the age of 18 living with them, 48.90% were married couples living together, 17.50% had a female householder with no husband present, and 29.40% were non-families. 25.40% of all households were made up of individuals, and 11.60% had someone living alone who was 65 years of age or older. The average household size was 2.57 and the average family size was 3.06. In the county, the population was spread out, with 25.30% under the age of 18, 9.20% from 18 to 24, 28.20% from 25 to 44, 22.70% from 45 to 64, and 14.60% who were 65 years of age or older. The median age was 36 years. For every 100 females there were 107.60 males. For every 100 females age 18 and over, there were 106.80 males. The median income for a household in the county was $26,533, and the median income for a family was $31,753. Males had a median income of $25,255 versus $19,607 for females. The per capita income for the county was $12,511. About 18.90% of families and 23.10% of the population were below the poverty line, including 30.10% of those under age 18 and 22.50% of those age 65 or over. Transportation Major highways Interstate 10 is the main interstate highway through Madison County, running west and east through the panhandle from Alabama to Jacksonville. Four interchanges exist in the county at US 221 south of Greenville, (Exit 241), SR 14 (Exit 251) and SR 53 (Exit 258) south