Ford's first automatic transmission, which appeared in its 1951 models, was referred to as the Ford-O-Matic. This basic unit was designed by
Borg-Warner and would become the platform from which many later model automatic transmissions would evolve.
Developed as a three-speed automatic, the Ford-O-Matic used a cast-iron case and would normally be started in second gear. For this reason, you often see the Ford-O-Matic referred to as a two-speed, although the only actual two-speed units were produced from 1959-'64, and they had aluminum cases.
A sprag was added to the planetary assembly in 1958 so that you could select whether to start out in first gear or second, and the Ford-O-Matic name was changed to
Cruise-O-Matic.