Glass-Steagall was originally passed to stop bank speculation with depositor's money on the NY Stock Exchange after the 1929 crash. The crash was caused by bank speculators on the Stock Exchange using average American's and businesses' deposits. In 1933, there were massive runs by depositors to retrieve what money was left in the banks from their own accounts. The money wasn't there anymore. So, in March 33, the Federal Government declared the National Bank Holiday that shut down all banks in the US.