Read this article. Some people contend that the beginning of World War II ended the Great Depression, while others suggest it was the end of World War II that brought economic restabilization.
Overview
After the Wall Street Crash of 1929, where the Dow Jones
Industrial Average dropped from 381 to 198 over the course of two
months, optimism persisted for some time. The stock market rose in early
1930, with the Dow returning to 294 (pre-depression levels) in April
1930, before steadily declining for years, to a low of 41 in 1932.
At
the beginning, governments and businesses spent more in the first half
of 1930 than in the corresponding period of the previous year. On the
other hand, consumers, many of whom suffered severe losses in the stock
market the previous year, cut expenditures by 10%. In addition,
beginning in the mid-1930s, a severe drought ravaged the agricultural
heartland of the U.S.
Interest rates dropped to low levels by
mid-1930, but expected deflation and the continuing reluctance of
people to borrow meant that consumer spending and investment remained
low. By May 1930, automobile sales declined to below the levels of
1928. Prices, in general, began to decline, although wages held steady
in 1930. Then a deflationary spiral started in 1931. Farmers faced a
worse outlook; declining crop prices and a Great Plains drought crippled
their economic outlook. At its peak, the Great Depression saw nearly
10% of all Great Plains farms change hands despite federal
assistance.
The decline in the U.S. economy was the factor
that pulled down most other countries at first; then, internal
weaknesses or strengths in each country made conditions worse or
better. Frantic attempts by individual countries to
shore up their economies through protectionist policies – such as the
1930 U.S. Smoot–Hawley Tariff Act and retaliatory tariffs in other
countries – exacerbated the collapse in global trade, contributing to
the depression. By 1933, the economic decline pushed world trade to
one third of its level compared to four years earlier.