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 Great Depression was not a sign of the failure of monetary policy or a result of the failure of the market system as was widely interpreted. It was instead a consequence of a very serious government failure, in particular a failure in the monetary authorities to do what they'd initially been set up to do.
The Great Depression in the United States was caused - I won't say caused, was enormously intensified and made far worse than it would have been by bad monetary policy.
