attach large trailers to tractors easily and safely and the freedom it gave them to switch out trailers. Without a fifth wheel, the modern distribution system would look quite different as drop-and-hook would not be easy. The semi-trailer increased the capacity of trucks, but it was the fifth wheel that brought the flexibility for drivers to keep moving while receivers unloaded the loads they just delivered. The Fruehauf Trailer Corporation helped to make the Martin Rocking 5th Wheel a success by installing them on their popular new semi-trailer design. August Fruehauf invented the semi-trailer in 1914 with their own 5th wheel hitch. They adopted the Martin Rocking 5th wheel in 1916. By 1916 Fruehauf was producing semi-trailers in tandem with Federal Truck. These two Detroit companies also contracted with the military in WWI sending a convoy of supplies, men and equipment from Detroit to Norfolk, Virginia shipyards for travel to the front in Europe. Fruehauf's success with semi-trailer sales surpassed the million dollar sales mark by 1920. Opening a branch in Chicago and later in Des Moines their trailers and hence, the Martin Rocking 5th Wheel became the top selling commercial vehicle of this era. Fruehauf's slogan, "A Horse can pull more than it can carry, so can a truck" became their advertising motto. Merchants, manufacturers and businesses in every industry clamored for a semi-trailer and the shuttle concept introduced by Fruehauf using one tractor truck and 2 or more semi-trailers. Fruehauf used the Martin Rocking 5th Wheel up until at least 1919. Early that year, the manual coupler was introduced to the industry by Fruehauf and the jacks acting as front supports for the semi-trailer were supplanted by wheels, raised and lowered manually. Fruehauf automatic semi-trailer In 1926, Fruehauf introduced the automatic semi-trailer in which the coupling and the uncoupling of the tractor were accomplished mechanically by the motion of the tractor. Fruehauf's introduction of the automatic semi-trailer was instantly recognized by transportation experts as a major contribution to the industry. The automatic semi-trailer coupling patented by Fruehauf dominated the semi-trailer market until the Fruehauf Trailer Corporation's assets were sold in bankruptcy to Wabash National in 1997. Later documentation for a patent of a fifth wheel is in patent number 2,053,812 issued to Charles E. Bradshaw of Wellville, Virginia, filed March 18, 1936 and granted September 8, 1936. One third of the patent was assigned to Charles Martin, also