By 1915 the US Army was using trucks tactically, for World War I it began purchasing in large numbers. Early trucks were often designed for both military and commercial use, later military-specific designs were built. Since 1940 the US military has ordered over 3,000,000 tactical trucks. The US Marines have used both US Army and their own specific models, some are shown. The "ton" (907 kg) weight ratings are the payload of a basic cargo version of the truck, not of the individual version. "Total built" usually includes for US forces and any export orders.