In the early days of the Great Depression, Rep. Willis Hawley, a Republican from Oregon, and Utah Republican Sen. Reed Smoot thought they had landed on a way to protect American farmers and manufacturers from foreign competition: tariffs.

President Herbert Hoover signed the Smoot-Hawley Tariff Act in 1930, even as many economists warned that the levies would prompt retaliatory tariffs from other countries, which is precisely what happened. The U.S. economy plunged deeper into a devastating financial crisis that it would not pull out of until World War II.