[308] The Revenue Act of 1942 instituted top tax rates as high as 94% (after accounting for the excess profits tax), greatly increased the tax base, and instituted the first federal withholding tax.[309] In 1944, Roosevelt requested that Congress enact legislation which would tax all "unreasonable" profits, both corporate and individual, and thereby support his declared need for over $10 billion in revenue for the war and other government measures. Congress overrode Roosevelt's veto to pass a smaller revenue bill raising $2 billion.[310]
In 1942, with the United States now in the conflict, war production increased dramatically but fell short of the goals established by the president, due in part to manpower shortages.[311] The effort was also hindered by numerous strikes, especially among union workers in the coal mining and railroad industries, which lasted well into 1944.[312][313] Nonetheless, between 1941 and 1945, the United States produced 2.4 million trucks, 300,000 military aircraft, 88,400 tanks, and 40 billion rounds of ammunition. The production capacity of the United States dwarfed that of other countries; for example, in 1944, the United States produced more military aircraft than the combined production of Germany, Japan, Britain, and the Soviet Union.