The United States developed the machinery and resources necessary to fight World War II through an unprecedented expansion of state power and government spending. Price and wage restrictions were placed on many sectors of the economy, production quotas were negotiated or mandated for many crucial industries, and rations were placed on crucial war materiel like gasoline, both to guard against shortages and to manage inflation.
A new bureaucracy was set up along New Deal lines to deal with the challenges of war production. As mentioned above, many of the agencies, loosely modeled on the apparatus of the New Deal, exercised an almost unprecedented amount of control over the American economy. The Office of Price Administration implemented price ceilings and the War Production Board dealt with essential industries, facilitating their shift from a civilian to a war footing.
The war effort was financed through massive expansion of income taxation as well as deficit spending. Millions of Americans bought war bonds, which would later mature, with the additional earnings they made during the war. Also, many Americans, including women and the elderly entered the workforce, filling positions either vacated by servicemen or created by the war effort.
All in all, however, the war effort depended on the sacrifices and exertions of millions of Americans. People dealt with privations and demands of a total war in ways that Americans had really never been asked to sacrifice in modern times. While these sacrifices were not always made as cheerfully as often portrayed in historical memory, they were unquestionably crucial to fighting and winning this massive conflict.