DUNCAN

city, seat (1907) of Stephens county, south central Oklahoma, U.S. Once a cow town on Chisholm Trail, it was founded officially in 1892 when the Rock Island Railroad reached the site. It was named for William Duncan, a pioneer trader and tailor from Fort Sill. After the discovery of oil in 1921, the petroleum industry replaced agriculture as the primary economic activity. Erle Halliburton initiated and developed there an oil-well cementing business that grew to worldwide importance. Inc. town, 1898; city, 1910. Pop. (1990) 21,732. the king of Scotland, who is murdered by Macbeth in William Shakespeare's Macbeth. His brutal murder sets in motion the upward political course and the downward moral course of Macbeth and his wife.