Plaquemine is a city in and the parish seat of Iberville Parish, Louisiana, United States. The population was 7,119 at the 2010 census. It is part of the Baton Rouge Metropolitan Statistical Area.
Plaquemine is located at 30°17′3″N 91°14′26″W / 30.28417°N 91.24056°W / 30.28417; -91.24056 (30.284044, −91.240485) and has an elevation of 23 feet (7.0 m). Plaquemine is located at the junction of Bayou Plaquemine and the Mississippi River. The city itself is surrounded by farmland; beyond the farmland to the west lies nearly uninhabited swampland.
According to the United States Census Bureau, the city has a total area of 3.0 square miles (7.8 km), of which 2.9 square miles (7.6 km) are land and 0.1 square miles (0.2 km), or 2.75%, are water.
As of the census of 2000, there were 7,064 people, 2,593 households, and 1,846 families residing in the city. The population density was 2,467.0 people per square mile (953.6/km²). There were 2,828 housing units at an average density of 987.6 per square mile (381.8/km²). The racial makeup of the city was 49.26% White, 49.60% African American, 0.17% Native American, 0.27% Asian, 0.03% Pacific Islander, 0.08% from other races, and 0.58% from two or more races. Hispanic or Latino of any race were 1.15% of the population.
There were 2,593 households out of which 29.7% had children under the age of 18 living with them, 44.0% were married couples living together, 22.7% had a female householder with no husband present, and 28.8% were non-families. 26.5% of all households were made up of individuals and 10.5% had someone living alone who was 65 years of age or older. The average household size was 2.64 and the average family size was 3.21.
In the city, the population was spread out with 25.8% under the age of 18, 8.9% from 18 to 24, 25.9% from 25 to 44, 22.8% from 45 to 64, and 16.5% who were 65 years of age or older. The median age was 37 years, higher than Louisiana’s median age of 34.0 years. For every 100 females, there were 88.2 males. For every 100 females age 18 and over, there were 82.3 males.
The median income for a household in the city was $28,364, and the median income for a family was $32,971. Males had a median income of $34,868 versus $21,016 for females. The per capita income for the city was $14,066. About 23.6% of families and 24.4% of the population were below the poverty line, including 35.8% of those under age 18 and 17.5% of those age 65 or over.