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 Recession
The Great Recession was a period of general economic decline observed in world markets during the late 2000s and early 2010s. The scale and timing of the recession varied from country to country. The International Monetary Fund concluded that the overall impact was the most severe since the Great Depression in the 1930s. The Great Recession stemmed from the collapse of the United States real-estate market, in relation to the financial crisis of 2007 to 2008 and U.S. subprime mortgage crisis of 2007 to 2009, though policies of other nations contributed also. According to the National Bureau of Economic Research (the official arbiter of U.S. recessions), the recession in the United States began in December 2007 and ended in June 2009, thus extending over 19 months. The Great Recession resulted in the scarcity of valuable assets in the market economy and the collapse of the financial sector (banks) in the world economy. Some banks were bailed out by the Federal government of the United States.