Signed by Herbert Hoover on June 17, 1930, over the public opposition of more than a thousand economists, the Smoot–Hawley Tariff Act raised average duties on dutiable imports to roughly 60 percent — among the highest in U.S. history. Trading partners retaliated in kind, world trade collapsed by more than two-thirds between 1929 and 1934, and the Depression deepened. Congress reversed course with the Reciprocal Trade Agreements Act of 1934, which delegated to the President authority to negotiate reciprocal tariff reductions — a delegation that eventually flowered into GATT (1947) and the modern free-trade framework. Smoot–Hawley is the textbook cautionary tale of protectionist overreach.