It is a typical misconception that the parish was named after Hernando de Soto, the Spaniard who explored the future southeastern United States and discovered and named the Mississippi River. The parish was in fact named after the unrelated Marcel DeSoto, who led the first group of European settlers there, to a settlement historically known as Bayou Pierre. The parish's name is also commonly misspelled following the explorer's name as "De Soto Parish," but it is properly spelled following the settler's name as "DeSoto Parish." The Battle of Mansfield was fought in DeSoto Parish on April 8, 1864. General Alfred Mouton was killed in the fighting, but his position was carried forward by Prince de Polignac, a native of France. The battle is commemorated at the Mansfield State Historic Site four miles south of Mansfield off Louisiana Highway 175. The Confederate victory prevented a planned Union invasion thereafter of Texas. Mansfield, also known as the Battle of Sabine Crossroads, a Confederate victory, occurred with one year and one day left in the duration of the war. Mansfield was quickly followed by the Battle of Pleasant Hill to the south.
Geography
According to the U.S. Census Bureau, the parish has a total area of, of which is land and is water.
As of the census of 2010, there were 32,000 people, 12,562 households, and 7,012 families residing in the parish. The population density was 29 people per square mile. There were 11,204 housing units at an average density of 13 per square mile. The racial makeup of the parish was 56.97% White, 38.16% Black or African American, 0.82% Native American, 0.41% Asian, 0.15% Pacific Islander, 0.54% from other races, and 0.66% from two or more races. 2.85% of the population were Hispanic or Latino of any race. There were 9,691 households out of which 33.50% had children under the age of 18 living with them, 48.70% were married couples living together, 18.60% had a female householder with no husband present, and 28.10% 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 2.60 and the average family size was 3.11. In the parish the population was spread out with 28.40% under the age of 18, 8.30% from 18 to 24, 26.30% from 25 to 44, 23.00% from 45 to 64, and 14.10% who were 65 years of age or older. The median age was 36 years. For every 100 females there were 90.80 males. For every 100 females age 18 and over, there were 87.00 males. The median income for a household in the parish was $28,252, and the median income for a family was $33,196. Males had a median income of $30,780 versus $20,182 for females. The per capita income for the parish was $13,606. About 21.00% of families and 25.10% of the population were below the poverty line, including 33.80% of those under age 18 and 24.90% of those age 65 or over.
