 After graduating, Winn worked for a Kansas City radio station for two years and, during World War II, worked for North American Aviation at Fairfax Field, north of Kansas City, Kansas, where the B-25 Mitchell bomber was manufactured.He then pursued a career in home building and was vice president of the Winn-Rau Corporation from 1950 until his election to Congress.Additionally, he was a director of the National Association of Home Builders for fourteen years and was president of the Home Builders Association of Kansas.