Agriculture, like every major industry, has a history of relentless innovation in search of efficiency. The combine harvester is named for its efficient combination of formerly separate, labor-intensive tasks of reaping, threshing, gathering, and winnowing grain. The countless field hands displaced from their arduous labor harvesting grain were replaced by a smaller number of workers with new skills. Some fed, drove, outfitted, and cared for horses (and later, tractors) while others designed, built, and maintained the latest in combine technology.

By 1936, tractor-powered combines were available, but bank failures and the challenging market conditions of the Great Depression slowed investments in innovation. During the 1930s, many farmers continued using horse-powered combine technology that had been in widespread use since the 1860s. America’s horse population had peaked at about 25 million in 1920, but power provided by tractors finally exceeded “horse-power” on North American farms by 1945. When new technology displaces workers today, we are reminded of these earlier waves of progress.