"They should have made liquidity available in exchange for good collateral. Instead they allowed massive bank failures and the money supply shrank by a third."
First.
This essentially summarizes Friedman and Schwartz's argument that:
The Federal Reserve failed to act as a lender of last resort.
Many banks that collapsed between 1929 and 1933 were solvent but illiquid—they needed emergency loans, not liquidation.
The Fed, prioritizing gold reserves and low inflation, stood by passively, allowing panic and bank runs to destroy confidence and credit.
As thousands of banks failed, the money supply (M1) contracted by roughly 33%, deepening and prolonging the Great Depression.