At the beginning of the decade, American business was adjusting to its new role in the world economy after the end of World War I (1914–18). During the war, America had supplied the Allied European participants with food, equipment, money, and, eventually, troops. The war had created an economic boom in America like no other before it. The war also linked America with other nations through trade; American business grew on the strength of equipment and materials orders from other countries.

The American government provided generous financial support to American businesses during the war, which spurred the growth of technologically advanced manufacturing throughout the country. Those industries most helped were automobile, aircraft, and radio manufacturers. These industries had existed before the war, but federal spending allowed them to grow into massive operations that employed thousands of people. The large number of employees could quickly produce...