Causes of the Great Depression
Second, there are the monetarists, who believe that the Great Depression started as an ordinary recession, but that significant policy mistakes by monetary authorities (especially the Federal Reserve) caused a shrinking of the money supply which greatly exacerbated the economic situation, causing a recession to descend into the Great Depression. Related to this explanation are those who point to debt deflation causing those who borrow to owe ever more in real terms.
Great Depression in the United States
The Great Depression began in the United States of America and quickly spread worldwide. It had severe effects in countries both rich and poor. Personal income, consumption, industrial output, tax revenue, profits and prices dropped, while international trade plunged by more than 50%. Unemployment in the U.S. rose to 25%, and in some countries rose as high as 33%.