|Jefferson County, Mississippi|
Location in the U.S. state of Mississippi
Mississippi's location in the U.S.
|Named for||Thomas Jefferson|
|• Total||527 sq mi (1,365 km2)|
|• Land||520 sq mi (1,347 km2)|
|• Water||7.3 sq mi (19 km2), 1.4%|
|• ( 2010)||7,726|
|• Density||15/sq mi (6/km2)|
|Time zone||Central: UTC−6/ −5|
Jefferson County is a county located in the U.S. state of Mississippi; its western border is formed by the Mississippi River. As of the 2010 census, the population was 7,726,  making it the third-least populous county in Mississippi. Its county seat is Fayette.  The county is named for U.S. President Thomas Jefferson. 
Originally developed as cotton plantations in the antebellum era, the rural county has struggled with a declining economy and reduced population since the mechanization of agriculture and urbanization of other areas. In 2014 its estimated population of 7599 was roughly one-third of the population peak in 1900. Within the United States, in 2009 rural Jefferson County had the highest percentage of African-Americans of any county. It was the fourth-poorest county in the nation. 
- Claiborne County (north)
- Copiah County (northeast)
- Lincoln County (southeast)
- Franklin County (south)
- Adams County (southwest)
- Tensas Parish, Louisiana (west)
|U.S. Decennial Census
1790-1960  1900-1990 
1990-2000  2010-2013 
As of the 2010 United States Census, there were 7,726 people residing in the county. 85.7% were Black or African American, 13.7% White, 0.2% Native American and 0.3% of two or more races. 0.4% were Hispanic or Latino (of any race).
As of the census  of 2000, there were 9,740 people, 3,308 households, and 2,338 families residing in the county. The population density was 19 people per square mile (7/km²). There were 3,819 housing units at an average density of 7 per square mile (3/km²). The racial makeup of the county was 13.06% White, 86.49% Black or African American, 0.08% Native American, 0.10% Asian, 0.01% Pacific Islander, 0.02% from other races, and 0.24% from two or more races. 0.66% of the population were Hispanic or Latino of any race. Jefferson County has the highest percentage of black residents of any U.S. county.
There were 3,308 households out of which 36.60% had children under the age of 18 living with them, 36.00% were married couples living together, 28.50% had a female householder with no husband present, and 29.30% were non-families. 27.10% 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 2.75 and the average family size was 3.36.
In the county, the population was much younger than the national average with 28.80% under the age of 18, 12.10% from 18 to 24, 28.50% from 25 to 44, 19.60% from 45 to 64, and 10.90% who were 65 years of age or older. The median age was 32 years. For every 100 females there were 99.00 males. For every 100 females age 18 and over, there were 99.00 males.
The median income for a household in the county was $18,447, and the median income for a family was $23,188. Males had a median income of $25,726 versus $18,000 for females. The per capita income for the county was $9,709. About 32.50% of families and 36.00% of the population were below the poverty line, including 46.00% of those under age 18 and 34.40% of those age 65 or over.
Jefferson County School District operates public schools.
- Fayette (county seat)
- Gum Ridge
- Old Greenville, original county seat (c 1799–1825); on the Natchez Trace
- Selsertown, another Natchez Trace town
- Abijah Hunt, merchant who lived in Old Greenville during the Territorial Period, and owned a chain of stores and public cotton gins along the Natchez Trace 
- David Hunt, Antebellum planter who lived on Woodlawn Plantation in Jefferson County, and became one of 12 planter millionaires in the Natchez District before the American Civil War.
- Zachary Taylor, U.S. President, planter, and soldier who often stayed on his plantation, Cypress Grove in Jefferson County, between 1840 and 1848.
|Wikimedia Commons has media related to Jefferson County, Mississippi.|
- Cypress Grove Plantation
- National Register of Historic Places listings in Jefferson County, Mississippi
- Prospect Hill Plantation
- Springfield Plantation (Fayette, Mississippi)
- Woodland Plantation (Church Hill, Mississippi)
- Wyolah Plantation
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