Above is a photo of a John Deere 4020 tractor, located in Osage County, Kansas. The 4020 was a farm tractor model made by John Deere from 1964 to 1972. It has a six-cylinder engine tested at 84 drawbar and 96 PTO horsepower. The 4020 is significant for its great popularity. Over 184,000 units were built. It was the most popular tractor of its time. Photo credit: Wikipedia.