Wagon

Wagon, wheeled vehicle of primary importance to transportation and commerce. The invention of the wagon coincided with that of the wheel, over 5,000 years ago, when solid wooden wheels were fixed to a simple axle attached to a sledge. Wheeled transport vehicles, hauled by oxen, developed in Mesopotamia. The Greeks and Romans improved vehicle design until after the fall of the Roman Empire, when little was done to advance the design of wheeled conveyance. Farm carts remained the most widely used transport until the development of 4-wheeled coaches in Germany in the Middle Ages. By the 17th century, in western Europe, a period of mechanical and scientific enlightenment had begun. Spring suspension came into use permitting longer-distanced travel at higher speeds. This led to development and improvement of commercial and passenger coaches and carriages, freight-transport vehicles, and ultimately to the invention of the automobile.