The Smoot-Hawley Tariff Act was a 1930 U.S. law that significantly raised import tariffs on over 20,000 foreign products to protect American businesses and farmers during the Great Depression. It increased tariffs by an average of 50%, but instead of helping the economy, it triggered retaliatory tariffs from other countries, causing a drastic decline in world trade. The Act is now considered a prime example of protectionist policies that worsened the global economic downturn.