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.
Long Depression
It was most notable in Western Europe and North America, at least in part because reliable data from the period is most readily available in those parts of the world. The United Kingdom is often considered to have been the hardest hit; during this period it lost some of its large industrial lead over the economies of Continental Europe. While it was occurring, the view was prominent that the economy of the United Kingdom had been in continuous depression from 1873 to as late as 1896 and some texts refer to the period as the Great Depression of 1873–1896.