El Dorado, city, seat of Union County, southern Arkansas; incorporated 1845. It is the center of a petroleum and natural-gas-producing area and has large oil refineries. Other products include chemicals and packaged poultry. The city is the site of a junior college. Settled in 1843, it was an agricultural and lumbering community until oil was discovered nearby in 1921. The city's name, Spanish for “the gilded one,” may refer to an early settler's recognition of the good fortune he found in the city. Population 25,270 (1980); 23,146 (1990); 21,530 (2000).
