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.
Huey Long
Long was a staunch opponent of the Federal Reserve System. Together with a group of House members and senators, Long claimed that the Federal Reserve's policies were the true cause of the Great Depression. Long made speeches denouncing the large banking houses of Morgan and Rockefeller centered in New York City, which owned stock in the Federal Reserve. He believed that these large bankers manipulated the monetary system to their own benefit, instead of that of the general public.