During the 1920s, what was the primary goal of a protective tariff?

Protective Tariffs have been used in order to protect the products inside of a country. Imagine that in America a shirt costs $100. Now imagine that an imported shirt from China that is the exact same as the American made shirts costs only $75. Which one is the consumer more likely to buy? But, if there was a import tariff of $25, then the shirts would cost the same. This is what a tariff is.