Final answer:
The Smoot-Hawley Tariff Act caused international trade to come to a halt because it created overly high prices for imported goods, leading to a sharp decline in trade.
Step-by-step explanation:
The act that caused international trade to come to a halt because of overly high prices for imported goods was the Smoot-Hawley Tariff Act. Enacted in 1930, this act raised tariff rates significantly, leading to other countries instituting their own retaliatory tariffs on U.S. goods. Despite intentions to protect American farmers and industries, it resulted in a sharp decline in international trade during the global depression, harming the U.S. economy and contributing to the severity of the Great Depression.