3. Smoot-Hawley triggers U.S. - Canada trade war
Things got even worse during the Great Depression. In 1930, Congress wanted to protect U.S. jobs from global trade. So the U.S. slapped tariffs on all countries that shipped goods to America in an effort to shield workers.
It was called the Smoot-Hawley Act. Today, it is widely accepted that this law made the Great Depression worse than it was.
Canada was furious, and retaliated more than any other country against the U.S., sparking a trade war.