According to the United States Census Bureau, the county has a total area of 347 square miles (900 km2), of which 343 square miles (890 km2) is land and 3.9 square miles (10 km2) (1.1%) is water.[6]
Marion County was formed in 1834 from part of Washington County.[7]
Marion County is Kentucky's most Catholic county. [citation needed]The first Catholic settlers in Kentucky came to Holy Cross in the western part of the county circa 1790. According to planar projection maps of Kentucky, Marion County includes the center of the state of Kentucky located 3 miles NNW of Lebanon just off KY 429. The actual physical center of Kentucky is disputed by surrounding counties[8] and due to use of planar methods[9] and projections used when the geographic centers of the United States were initially determined.
U.S. Decennial Census[11] 1790-1960[12] 1900-1990[13] 1990-2000[14] 2010-2020[1]
As of the census of 2000, there were 18,212 people, 6,613 households, and 4,754 families residing in the county. The population density was 53 per square mile (20/km2). There were 7,277 housing units at an average density of 21 per square mile (8.1/km2). The racial makeup of the county was 89.17% White, 9.12% Black or African American, 0.09% Native American, 0.43% Asian, 0.01% Pacific Islander, 0.35% from other races, and 0.82% from two or more races. 0.79% of the population were Hispanic or Latino of any race.
There were 6,613 households, out of which 35.60% had children under the age of 18 living with them, 53.80% were married couples living together, 13.70% had a female householder with no husband present, and 28.10% were non-families. 24.40% of all households were made up of individuals, and 10.10% had someone living alone who was 65 years of age or older. The average household size was 2.58 and the average family size was 3.06.
By age, 25.20% of the population was under 18, 9.90% from 18 to 24, 30.30% from 25 to 44, 21.70% from 45 to 64, and 12.80%were 65 years or older. The median age was 35 years. For every 100 females there were 102.30 males. For every 100 females age 18 and over, there were 101.60 males.
The median income for a household in the county was $30,387, and the median income for a family was $35,648. Males had a median income of $27,826 versus $20,699 for females. The per capita income for the county was $14,472. About 15.80% of families and 18.60% of the population were below the poverty line, including 21.80% of those under age 18 and 17.90% of those age 65 or over.
^"Find a County". National Association of Counties. Retrieved June 7, 2011.
^E., Kleber, John; Kentucky, University Press of; Policy, Institute for Regional Analysis and Public; Library, Camden-Carroll; University, Morehead State (2000). "The Kentucky Encyclopedia". www.kyenc.org. Retrieved July 4, 2018. {{cite web}}: |last3= has generic name (help)CS1 maint: multiple names: authors list (link)
