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 in the United States
The Great Recession in the United States was a severe financial crisis combined with a deep recession. While the recession officially lasted from December 2007 to June 2009, it took several years for the economy to recover to pre-crisis levels of employment and output. This slow recovery was due in part to households and financial institutions paying off debts accumulated in the years preceding the crisis along with restrained government spending following initial stimulus efforts. It followed the bursting of the housing bubble, the housing market correction and subprime mortgage crisis.