"The term 'fifth wheel' comes from a similar coupling used on four-wheel horse-drawn carriages and wagons. The device allowed the front axle assembly to pivot in the horizontal plane, to facilitate turning. Basically a wheel was placed on the rear frame section of the truck, which back then only had four wheels, this wheel that was placed on the frame was the "fifth wheel" hence the name."
Just incase anyone was curious...beer and a computer are a dangerous combination for me
