Herbert Hoover signed the Smoot–Hawley Tariff Act shortly before the 1929 Wall Street Crash deepened.
Hoover became president in March 1929 and signed the tariff law on June 17, 1930, after the initial October 1929 market collapse. The act raised U.S. tariffs on thousands of imported goods. Its timing is important: it followed the crash rather than preceding it, although later trade contraction worsened the economic environment.
The law is named for Senator Reed Smoot and Representative Willis Hawley. Many trading partners retaliated with tariffs of their own, contributing to a sharp decline in international trade during the Great Depression.
A common mistake is to say Smoot–Hawley caused the October 1929 crash. The crash began months before the act became law, and historians identify multiple causes for both the market collapse and the Depression. Hoover’s successor, Franklin D. Roosevelt, took office in 1933.