About Dupo, Illinois
Coordinates: 38°30?57?N 90°12?29?W? / ?38.51583°N 90.20806°W? / 38.51583; -90.20806Dupo is a village in St. Clair County, Illinois, United States. The population was 3,933 at the 2000 census. The village was settled in about 1750 and was incorporated in 1876. Its name is derived from Prairie du Pont (French: Bridge Prairie).