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

By mid-1930, interest rates had dropped to low levels, but expected deflation and the continuing reluctance of people to borrow meant that consumer spending and investment were depressed. By May 1930, automobile sales had declined to below the levels of 1928. Prices in general began to decline, although wages held steady in 1930; but then a deflationary spiral started in 1931. Conditions were worse in farming areas, where commodity prices plunged, and in mining and logging areas, where unemployment was high and there were few other jobs.
The decline in the US 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 to shore up the economies of individual nations 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. By late 1930, a steady decline in the world economy had set in, which did not reach bottom until 1933.