Biography: From Wikipedia, the free encyclopedia Leonard Ray Dawson (born June 20, 1935) is a former American football quarterback who played professionally in the National Football League (NFL) and American Football League (AFL) for 19 seasons, primarily with the Kansas City Chiefs franchise. Dawson began his professional career in 1957 with the Pittsburgh Steelers of the NFL and also played for the Cleveland Browns. He left the NFL in 1962 to sign with the AFL's Chiefs (then known as the Dallas Texans), where he spent the last 14 seasons of his career, and rejoined the NFL after the AFL–NFL merger.