The 1st automatic transmission to work with a torque converter (as an alternative to a fluid coupling) was the Buick Dynaflow, which was launched for that 1948 design calendar year. In standard driving, the Dynaflow employed only the top gear, depending on the torque multiplication in the torque convertor at https://shaneubdcc.dm-blog.com/34164386/gearbox-auto-no-further-a-mystery