ELDORADO, a city in the oilfields of south-eastern Kansas, U.S.A., 3imi. N.E. of Wichita; the county seat of Butler county. It is on Federal highways 54 and 77, and is served by the Missouri Pacific and the Santa Fe Railways. The population was 3,129 in 191o; 10,995 in 192o (95% native white) ; and 10,311 in 193o Federal census. It is the shipping and supply centre for a farming, stock-raising and oil-producing region.