The United States had initiated conscription before the war, enlisting millions into the United States Armed Forces during peacetime. As the United States entered World War II, Congress expanded the draft, and by the end of the war, nearly 12 million people had joined the armed forces.

Prior to the United States' entry into World War II, President Roosevelt had directed the economy into the preparation for war. Soon after entry into the war, the United States' economy was fully converted into a wartime economy. American manufacturers, such as automobile manufacturers, switched production from consumer goods to military vehicles and equipment. Aircraft and warship production also increased.

The conversion to a wartime economy brought the Great Depression to an end.

The United States government played a pivotal role in directing the United States Armed Forces as well as maintaining the civilian army of the American home front. Several government agencies were created to lead citizens at home. The government increased defense spending; taxes were increased to help create more revenue.