The financial crisis that began in the summer of 2007 took a turn for the worse in September 2008. Until then, Federal Reserve actions taken to improve the functioning financial markets did not affect the monetary base. The unusual lending and purchase of private debt was offset by the sale of Treasury securities so that the total size of the balance sheet of the Fed remained relatively unchanged. In September, however, the Fed stopped selling securities as it made massive purchases of private debt and issued hundreds of billions of dollars in short-term loans. The result was a doubling of the size of the monetary base in the final four months of 2008. This article discusses the details of the programs that the Fed has initiated since the crisis began, shows which programs have grown as the monetary base grew, and discusses some factors that will determine whether this rapid increase in the monetary base will lead to rapid inflation.