Herbert Hoover was the U.S. president during the 1929 Wall Street crash and signed the Smoot–Hawley Tariff Act.
Hoover took office in March 1929, months before the stock market's dramatic collapse that autumn. The crash began during a broader period of economic weakness and financial instability, although historians do not treat the crash alone as the sole cause of the Great Depression.
In June 1930, Hoover signed the Smoot–Hawley Tariff Act, which raised U.S. tariffs on many imported goods. Other countries responded with tariff increases of their own. The law is widely associated with a contraction in international trade, though economists continue to debate the precise size of its contribution to the Depression.
Hoover's administration also supported public works, banking measures, and other interventions, but the economic crisis deepened during his presidency. Franklin D. Roosevelt defeated Hoover in the 1932 election and began his first term in March 1933. This timeline helps distinguish Hoover's response from the New Deal that followed.