Great Depression

The period about 1929-40, a period of sustained economic problems for the industrialized countries of the world, is known as The Great Depression. Following a sharp drop in stock markets in October, 1929, production and employment in the United States declined steadily until the middle of the ninteen-thirties, recovered somewhat, and then declined again. In the worst periods, about one-third of the American work force was out of work. Details and dates of economic decline varied from country to country, and to some extent from one industry and region to another; but generally the Great Depression ended in the frenzy of war production in World War II.

For more detail, see the following material from the chapters on macroeconomics:

Recessions
Cyclical Unemployment