The Federal Reserve the privately owned U.S. central bank definitely caused The Great Depression by contracting the amount of currency in circulation by one third from 1929 to 1933.
The Depression, which started in 1929 was rather mild from 1929 to 1930. And, indeed, in my opinion would have been over in 1931 at the latest had it not been that the Federal Reserve followed a policy which led to bank failures, widespread bank failures, and led to a reduction in the quantity of money.
