Assumption Parish (French: Paroisse de l’Assomption) is a parish located in the U.S. state of Louisiana. As of the 2010 census, the population was 23,421. Its parish seat is Napoleonville. Assumption Parish was established in 1807, as one of the original parishes of the Territory of Orleans.
According to the U.S. Census Bureau, the parish has a total area of 365 square miles (950 km), of which 339 square miles (880 km) is land and 26 square miles (67 km) (7.1%) is water.
As of the 2010 United States census, there were 23,421 people residing in the parish. 66.8% were White, 30.5% Black or African American, 0.6% Native American, 0.2% Asian, 0.1% Pacific Islander, 1.0% of some other race and 0.9% of two or more races. 2.1% were Hispanic or Latino (of any race). 38.2% were of French, French Canadian or Cajun and 9.4% American ancestry.
As of the census of 2000, there were 23,388 people, 8,239 households, and 6,311 families residing in the parish. The population density was 69 people per square mile (27/km²). There were 9,635 housing units at an average density of 28 per square mile (11/km²). The racial makeup of the parish was 67.17% White, 31.52% Black or African American, 0.31% Native American, 0.24% Asian, 0.01% Pacific Islander, 0.17% from other races, and 0.59% from two or more races. 1.21% of the population were Hispanic or Latino of any race. 81.14% of the population over the age of five spoke only English at home, while 17.58% reported speaking French or Cajun French .
There were 8,239 households out of which 37.90% had children under the age of 18 living with them, 56.80% were married couples living together, 14.90% had a female householder with no husband present, and 23.40% were non-families. 20.30% of all households were made up of individuals and 9.20% had someone living alone who was 65 years of age or older. The average household size was 2.81 and the average family size was 3.26.
In the parish the age distribution of the population shows 28.50% under the age of 18, 9.80% from 18 to 24, 28.70% from 25 to 44, 22.20% from 45 to 64, and 10.90% who were 65 years of age or older. The median age was 34 years. For every 100 females there were 93.90 males. For every 100 females age 18 and over, there were 90.90 males.
The median income for a household in the parish was $31,168, and the median income for a family was $36,052. Males had a median income of $35,941 versus $18,065 for females. The per capita income for the parish was $14,008. About 19.50% of families and 21.80% of the population were below the poverty line, including 28.40% of those under age 18 and 21.70% of those age 65 or over.