The Great Depression (1929-39) was the deepest and longest-lasting economic downturn in the history of the Western industrialized world. In the United States, the Great Depression began soon after the stock market crash of October 1929, which sent Wall Street into a panic and wiped out millions of investors.By 1933, when the Great Depression reached its nadir, some 13 to 15 million Americans were unemployed and nearly half of the country’s banks had failed. 

 

(source: http://www.history.com)