TRACTOR WARS traces the evolution of mechanical farming and chronicles the fight between three companies to build the first all-purpose tractor. For thousands of years, farming was driven by the muscle of either animals or humans. With the invention of the steam engine, industrialists brought steam power to farms. Then, inventions such as the reaper and steel plow catalyzed a rush to mechanize farming. By the 1920s, John Deere, Ford and International Harvester had emerged as leaders in the battle to develop a reliable tractor that would become part of everyday agriculture. By 1929, these three were among the few dozen companies that remained, but the tractor form people recognize today had finally emerged and began rapidly replacing muscle as the primary source of power on the farm.