Great Depression in the United States, worst and longest economic collapse in the history of the modern industrial world, lasting from the end of 1929 until the early 1940s.

Полностью нормализовалось только к концу войны

VIII End of the Depression

Although economic conditions improved by the late 1930s, unemployment in 1939 was still about 15 percent. However, with the outbreak of World War II in Europe in September 1939, the U.S. government began expanding the national defense system, spending large amounts of money to produce ships, aircraft, weapons, and other war material. This (война!) stimulated industrial growth, and unemployment declined rapidly. After the United States entered the war in December 1941, all sectors of the economy were mobilized to support the war effort. Industry greatly expanded, and unemployment was replaced by a shortage of workers.