The US used mainly two wheeled amphibians during WWII: the 1/4-ton GPA and the 2-1/2-ton DUKW. Although the former was a Ford Motor Company product and the later carried the label of archrival General Motors, they bore a similarity due to their common designer, Roderick Stephens. Despite their shared origins and cutting-edge design, the GPA and DUKW had vastly contrasting careers. Production of the GPA, essentially an amphibious Jeep, ended in 1943, just as the career of the DUKW, a virtual aquatic truck, was on its way to becoming the “gold standard” by which other amphibians are still measured. After taking part in the Allied invasion of Sicily in July 1943, the DUKW went on to see action in nearly every other US amphibious landing in WWII and returned to see service during the Korean War as well. Read Less