The United States mobilized for war after the attack on Pearl Harbor.

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…that accomplished wartime objectives with minimum hardship and dislocation. Sometimes execution of this effort was messy, with overlapping agencies and construction and supply lagging behind recruitment, but the World War II experience in the development and use of American industrial capacity may well be remembered as the classic case of economic mobilization, running the gamut from planning, through the buildup, to full-scale war production, and finally, demobilization. (http://www.army.mil/cmh-pg/documents/mobpam.htm)