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.
1930s
After the Wall Street Crash of 1929, the largest stock market crash in American history, most of the decade was consumed by an economic downfall called the Great Depression that had a traumatic effect worldwide, leading to widespread unemployment and poverty, especially in the United States, an economic superpower, and Germany, who had to deal with the reparations regarding World War I. The Dust Bowl (which gives the nickname the Dirty Thirties) in the United States further emphasised the scarcity of wealth. Herbert Hoover worsened the situation with his failed attempt to balance the budget by raising taxes. Franklin D. Roosevelt was elected, as a response, in 1933, and introduced the New Deal. The founding of the Civilian Conservation Corps (CCC) and the funding of numerous projects (e.g. the Hoover Dam) helped restore prosperity in the US.