Tom Mix was the major rival of Jack Armstrong in the world of juvenile adventure serials. These two defined the era: they opened and closed it, each spanning more than 15 seasons and both drawing consistently high ratings in the wheat-and-barley hour, 5-6 p.m.

Mix was created as an advertising vehicle for the Ralston Purina Company, which sponsored it throughout. The seasons generally spanned late September to late March or April in the early years, year round later. _{John Dunning}