All US civilian car and truck production came to a halt early in 1942. From then on all plants were fully engaged on war production, the volume of which had gradually increased from 1940. Not all automobile
manufacturers produced military vehicles; many plants turned out aircraft engines and components, artillery shells, machine guns, AA guns and other munitions.
In 1943 the Automotive Council for War Production announced that the automotive industry had supplied war material to the value of $13 billion and that 1038 automotive plants throughout the nation voluntarily co-operated to maintain maximum production.