Allis Chalmers/Cooper winch tractors date from the late 1930's. Allis Chalmers was a U.S. machinery manufacturer, and the Fred E. Cooper Company was an oil field drilling and service company in Tulsa, Oklahoma, that also built rigs. Cooper used Allis Chalmers tractors as a platform for drilling and service rigs. Although most wells in Borger's early oilfield were drilled with wooden rigs constructed on site, the discovery field also became a testing ground for new ideas and innovation. Cooper's winch tractor grew from practical knowledge gained on the job in this relatively new profession. These self-propelled rigs could be driven to a well site, making them more efficient, convenient, and cost-effective for drilling and oil field service companies. This model could also be used to service wells, which required constant repair, cleaning, and maintenance. Equipment capable of handling most of a company's heavy lifting was especially attractive to owner-operators. An advertisement for this kind of rig appeared in a July 24, 1941, issue of The Oil and Gas Journal shortly before the attack on the U.S. Navy base at Pearl Harbor, Hawaii, which started World War II.