History: The Great Depression, 1939-1943, United States

Some economies started to recover by the mid-1930s; in many countries the negative effects of the Great Depression lasted until the start of World War II.
Start of the Great Depression
Economic historians usually attribute the start of the Great Depression to the sudden devastating collapse of US stock market prices on October 29, 1929, known as Black Tuesday; some dispute this conclusion, and see the stock crash as a symptom, rather than a cause, of the Great Depression.