Cordia Sloan Duke chronicled a unique era in the history of the Southwest. Born in Belton, Missouri, she taught school in Indian Territory, Oklahoma, at 17. In 1907, she married Robert L. Duke, a ranch hand who had risen to division manager of the XIT Ranch, then the world's largest. In addition to her own family, she looked after the 150 cowboys who worked the 3,000,000-acre spread. She kept a diary of everyday events in ranch life around her and successfully encouraged 81 others to do likewise, preserving an authentic account of a passing phase of American life, the cowboy and his work.