The Great Depression was a severe global economic downturn from 1929 to 1939. The period was characterized by high rates of unemployment and poverty, drastic reductions in industrial production and international trade, and widespread bank and business failures around the world. The economic contagion began in 1929 in the United States, the largest economy in the world, with the devastating Wall Street stock market crash of October 1929 often considered the beginning of the Depression. Among the countries with the most unemployed were the U.S., the United Kingdom, and Germany.

The Depression was preceded by a period of industrial growth and social development known as the "Roaring Twenties". Much of the profit generated by the boom was invested in speculation, such as on the stock market, contributing to growing wealth inequality. Banks were subject to minimal regulation, resulting in loose lending and widespread debt. By 1929, declining spending had led to reductions in manufacturing output and rising unemployment. Share values continued to rise until the October 1929 crash, after which the slide continued until July 1932, accompanied by a loss of confidence in the financial system. By 1933, the U.S. unemployment rate had risen to 25%, about one-third of farmers had lost their land, and 9,000 of its 25,000 banks had gone out of business.