A pretty good marker date would be 1920. Henry Ford's Model T had been produced for a dozen years and production from his Detroit factory had become dazzling, more than a million a year coming off the assembly line. So many were being sold that Ford didn't bother to advertise. Conversely, Studebaker, which had been the largest maker of wagons, carriages and buggies, stopped production of all horse-drawn vehicles and focused on making automobiles as well. Uncle Dave Macon would have to give up his horse-powered haulage business and become a full-time banjo playing entertainer: and he never failed to take a jab at Henry Ford's cars when given the chance to put it into a song.

Horse drawn vehicles would continue for a while longer, but really, after 1920 everyone knew which way things were headed.