You clearly know nothing

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 world. After 1942, the U.S. began to promote worldwide free trade. After the 2016 presidential election, the US increased trade protectionism.[2]

https://en.wikipedia.org/wiki/History_of_tariffs_in_the_United_States