Deflation
Deflation occurred periodically in the U.S. during the 19th century (the most important exception was during the Civil War). This deflation was at times caused by technological progress that created significant economic growth, but at other times it was triggered by financial crises — notably the Panic of 1837 which caused deflation through 1844, and the Panic of 1873 which triggered the Long Depression that lasted until 1879. These deflationary periods preceded the establishment of the U.S. Federal Reserve System and its active management of monetary matters. Episodes of deflation have been rare and brief since the Federal Reserve was created (a notable exception being the Great Depression) while U.S. economic progress has been unprecedented.
Great Depression in the United States
By 1936, all the main economic indicators had regained the levels of the late 1920s, except for unemployment, which remained high. In 1937, the American economy unexpectedly fell, lasting through most of 1938. Production declined sharply, as did profits and employment. Unemployment jumped from 14.3% in 1937 to 19.0% in 1938. A contributing factor to the Recession of 1937 was a tightening of monetary policy by the Federal Reserve. The Federal Reserve doubled reserve requirements between August 1936 and May 1937 leading to a contraction in the money supply.