Dupo is a village in St. Clair County, Illinois, United States. The population was 4,138 at the 2010 census, an increase from 3,933 in 2000. The village was settled in about 1750 and was incorporated in 1876. Its name is derived from Common Fields of Prairie du Pont (French: Bridge Prairie). Dupo is located at 38°30′57″N 90°12′29″W (38.515702, -90.207992). It is located in the American Bottom floodplain of the Mississippi River. According to the 2010 census, Dupo has a total area of 4.42 square miles (11.45 km2), all land.Dupo had its start ca. 1905 when the railroad was extended to that point. The name is an abbreviation of DuPont.
In 2010 there were 4,138 people, 1,650 households, and 1,142 families residing in the village. The Population Density was 655 people per square mile(252.8/km2). There were 1,863 housing units at an average density of 294.8 per square mile (113.80/km2). The racial makeup of the village was 94.9% White, 2.3% African American, 0.4% Native American, 0.3% Asian, 0.3% from other races, and 1.8% from two or more races. Hispanic or Latino of any race were 1.4% of the population. There were 1,650 households, out of which 31.3% had children under the age of 18 living with them, 43.8% were married couples living together, 17.7% had a female householder with no husband present with 10.8% of all households having a female householder with kids.
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