As America's war effort ramped up in 1917, there was a collective realization that the fleet of vehicles needed to support a semi-mechanized army needed some standardization. The Liberty truck was the solution. It was designed by the Motor Transport section of the Quartermaster Corps in cooperation with the members of the Society of Automotive Engineers. A group of leading automotive engineers was summoned to Washington in 1917 to design standardized trucks for the AEF. It took took 50 men 69 days to design a 1-½ ton "A" model and the 3–5 ton "B" model. Production of the Liberty B began in the fall of 1917, and the first models were delivered to the secretary of war on 19 October. Of the almost 9,500 produced by 15 manufacturers, more than 7,500 were sent overseas. The Liberty's four-speed transmission coupled with its 52-hp engine gave the truck a top speed of about 15 miles per hour.
Sources: Photo, Wiki Commons; Data, American Military Vehicles of World War I by Albert Mroz