The 7.1-cent Tractor coil stamp, the 28th in the Transportation Series was issued February 6 in Sarasota, Florida by the U.S. Postal Service.
The 7.1-cent denomination represents the rate for third-class nonprofit mail which has been presorted by five-digit ZIP codes.
Ken Dallison of Indian River, Ontario, Canada, designed the Tractor stamp. His previous designs include the 11-cent Stutz Bearcat and 12-cent Stanley Steamer stamps in the Transportation Series, and the 33-cent Alfred Verville airmail stamp, all issued in 1985.
The Tractor stamp is being produced in unprecanceled and precanceled forms. The precanceled version includes the legend 'Nonprofit Org.' in two lines of black type. The design and the remaining lettering and numerals are dark red.
Tractors have a variety of uses, but the farm tractor is considered the most important because it revolutionized agricultural production in the United States.
With the advent in 1890 of the internal-combustion engine tractor (a word coined by combining parts of the words TRACtion and motTOR), huge areas of land were brought into production, crop yields were increased and acreage previously used to grow farm work-animal feed was converted to crops for human consumption.
Until the 1920s, the tractor was regarded primarily as a mobile source of power for operating stationary equipment such as a threshing cylinder and as a substitute for draft animals. But the value of farm tractors was boosted greatly by the introduction of the 'power takeoff,' which allowed rotary power from the engine to be transmitted through a flexible shaft to drive such field implements as hay balers, combines and mowing machines.
Such mechanization allows one farm worker to produce all the food and fibers required by 20 other persons, as well as surpluses for export or for use as raw materials for chemical processes.
The 1920s model depicted on the Tractor stamp is typical of all such vehicles produced before 1932 in that it was equipped with steel tires dotted with ground-gripping lugs. However, these wheels greatly disturbed the soil, raised rolling resistance and lowered power-transmitting efficiency, which sparked development of the rubber tractor tire.
Similarly, the 1920s tractor, with its two sets of widely spaced wheels, was well designed for pulling large loads but was not suited for cuiltivating crops that are planted in rows. That need was filled by the row-crop tractor which, with its closely spaced front wheels and adjustable axles, is the most popular type of tractor in use today.