Tariffs have historically served a key role in the trade policy of the United States. Their purpose was to generate revenue for the federal government and to allow for import substitution industrialization (industrialization of a nation by replacing foreign imports with domestic production) by acting as a protective barrier around infant industries. They also aimed to reduce the trade deficit and the pressure of foreign competition. Tariffs were one of the pillars of the American System that allowed the rapid development and industrialization of the United States. The United States pursued a protectionist policy from the beginning of the 19th century until the middle of the 20th century. Between 1861 and 1933, they had one of the highest average tariff rates on manufactured imports in the