|• Total||3.0 sq mi (7.7 km2)|
|• Land||3.0 sq mi (7.7 km2)|
|• Water||0.0 sq mi (0.0 km2)|
|Elevation||410 ft (125 m)|
|• Density||1,299.2/sq mi (501.6/km2)|
|Time zone||Central (CST) (UTC-6)|
|• Summer (DST)||CDT (UTC-5)|
|GNIS feature ID||1354578|
Clarksville is a city in Red River County, Texas, in the United States in the northernmost part of the Piney Woods region of East Texas. As of the 2000 census, the city population was 3,883. It is the county seat of Red River County.
Clarksville is located at .(33.611086, -95.052448)
According to the United States Census Bureau, the city has a total area of 3.0 square miles (7.8 km2), all of it land.
As of the census of 2000, there were 3,883 people, 1,530 households, and 1,006 families residing in the city. The population density was 1,299.2 people per square mile (501.4/km²). There were 1,787 housing units at an average density of 597.9 per square mile (230.8/km²). The racial makeup of the city was 53.39% White, 42.18% African American, 0.21% Native American, 0.26% Asian, 3.01% from other races, and 0.95% from two or more races. Hispanic or Latino of any race were 7.29% of the population.
There were 1,530 households out of which 31.4% had children under the age of 18 living with them, 42.3% were married couples living together, 19.1% had a female householder with no husband present, and 34.2% were non-families. 31.5% of all households were made up of individuals and 16.8% had someone living alone who was 65 years of age or older. The average household size was 2.44 and the average family size was 3.04.
In the city the population was spread out with 26.8% under the age of 18, 8.6% from 18 to 24, 25.4% from 25 to 44, 18.9% from 45 to 64, and 20.3% who were 65 years of age or older. The median age was 37 years. For every 100 females there were 85.4 males. For every 100 females age 18 and over, there were 78.7 males.
The median income for a household in the city was $23,655, and the median income for a family was $31,729. Males had a median income of $21,635 versus $16,189 for females. The per capita income for the city was $13,487. About 17.6% of families and 23.7% of the population were below the poverty line, including 39.2% of those under age 18 and 15.1% of those age 65 or over.
The area is served by the Clarksville Independent School District.
Bill Hankins of The Paris Daily News was first to write an article about the arrest of Clarksville High School basketball coach, Vergil Richardson, in December 2007  and continued to follow the story closely for years.
In November 2010 NPR aired a story about racism in Clarksville  that discussed the controversial arrest of the high school basketball coach and other family members during Thanksgiving dinner in 2007. In 2007 former Clarksville High School basketball star and coach of the team at the time, Vergil Richardson, was at Thanksgiving dinner with five other family members when police stormed the family home arresting Vergil and five of his family members. Vergil's 25-year-old half brother, Kevin Calloway, was the target as he admittedly had been selling drugs. The controversy began when police decided to charge all six family members arrested with manufacturing, distributing, and possessing narcotics despite Kevin's insistence that he had acted alone, stashing the drugs in the shed in the yard locked with a key only he possessed. The Richardsons hired the high-profile trial attorney Mark Lesher who immediately discovered that the District Attorney had participated in the raid and that the warrant for the raid was issued after the raid was conducted. State prosecutors moved to dismiss the charges on all the Richardsons except for Kevin Calloway but Judge John Miller refused to do so. Lesher then filed a motion to dismiss Judge Miller, arguing the judge was biased; in a rare moment of cooperation, prosecutors supported the motion. The newly-appointed judge immediately dismissed the charges.
The Richardsons filed a lawsuit against the Red River County Sheriff, District Attorney, and Chief of Police in November 2009 and are set to begin proceedings in 2011,which was over 2 years ago.
Clarksville is the birthplace of:
- John Williams, author of Stoner and National Book Award co-winner Augustus.
- Euell Gibbons, author of cookbooks and foraging guides, proponent of natural diets, and television personality popular in the 1960s and 1970s
- J. D. Tippit, a Dallas police officer who was shot and killed by Lee Harvey Oswald a few hours after Oswald assassinated President John F. Kennedy.
- Barney Cannon, a country music deejay long associated with radio station KWKH in Shreveport, Louisiana, got his start in Clarksville in 1972.
- William Humphrey, author of National Book Award nominee "Home from the Hill". The book was made into a movie shot on location in and around Clarksville in the late 1950s.
- Tommie Smith set the world and Olympic records with a time of 19.83 seconds and became the 200-meter Olympic champion at the 1968 Summer Olympics, which were held in Mexico.
- "American FactFinder". United States Census Bureau. Retrieved 2008-01-31.
- "US Board on Geographic Names". United States Geological Survey. 2007-10-25. Retrieved 2008-01-31.
- "Find a County". National Association of Counties. Retrieved 2011-06-07.
- "US Gazetteer files: 2010, 2000, and 1990". United States Census Bureau. 2011-02-12. Retrieved 2011-04-23.
- "Former coach arrested on drug charges". The Paris News. 8 December 2007. Retrieved 1 January 2011.
- "Civil Rights Judicial Bias Surround Texas Drug Case". NPR.org. 23 November 2010. Retrieved 1 January 2011.
- "Richardson Refiles Lawsuit". The Paris News. 24 November 2009. Retrieved 1 January 2011.