Great Depression and its causes from the perspective of economic theories

The Great Depression was the greatest economic downturn in 20th century. In my work I describe a period before the crisis, and the collapse of the American Stock Exchange, which is often wrongly considered as the beginning of crisis. Main economical theories saw different reasons of crisis. Keynesians saw the biggest problem in the lack of aggregate demand and the solutions they saw in government stimulation of demand. Austrian school with this theory completely disagreed and saw just the biggest mistake of the government interventions that deepened the crisis. Monetarists saw the biggest problem in the failure of the Federal Reserve, which failed at the time of distress, when it should get adequate amount of money to banks. Saw a possible solution in reducing the interest rate and Federal reserve should purchase government bonds held by commercial banks. The United States got out of the crisis thanks to government spending during the World War II