In the United States, the Great Depression began with the Wall Street Crash of October 1929 and then spread worldwide. The nadir came in 1931–1933, and recovery came in 1940. The stock market crash marked the beginning of a decade of high unemployment, poverty, low profits, deflation, plunging farm incomes, and lost opportunities for economic growth as well as for personal advancement. Altogether, there was a general loss of confidence in the economic future. The usual explanations include numerous factors, especially high consumer debt, ill-regulated markets that permitted overoptimistic loans by banks and investors, and the lack of high-growth new industries. These all interacted to create a downward economic spiral of reduced spending, falling confidence and lowered production. Industries that suffered the most included construction, shipping, mining, logging, and agriculture. Also hard hit was the manufacturing of durable goods like automobiles and appliances, whose purchase consumers could postpone. The economy hit bottom in the winter of 1932–1933; then came four years of growth until the recession of 1937–1938 brought back high levels of unemployment. The Depression caused major political changes in America. Three years into the depression, President Herbert Hoover, widely blamed for not doing enough to combat the crisis, lost the election of 1932 to Franklin Delano Roosevelt by a landslide. Roosevelt's economic recovery plan, the New Deal, instituted unprecedented programs for relief, recovery and reform, and brought about a major realignment of politics with liberalism dominant and conservatism in retreat until 1938. There were mass migrations of people from badly hit areas in the Great Plains (the Okies) and the South to places such as California and the cities of the North (the Great Migration). Racial tensions also increased during this time. The memory of the Depression also shaped modern theories of government and economics and resulted in many changes in how the government dealt with economic downturns, such as the use of stimulus packages, Keynesian economics, and Social Security. It also shaped modern American literature, resulting in famous novels such as John Steinbeck's The Grapes of Wrath and Of Mice and Men. Causes Monetary interpretations Examining the causes of the Great Depression raises multiple issues: what factors set off the first downturn in 1929; what structural weaknesses and specific events turned it into a major depression; how the downturn spread from country to country; and why the economic recovery was so prolonged. Many rural banks began to