I remember the first time I ever heard the term tariff was in my first economics course in college. A tariff is a tax applied to imported goods and collected by the federal government. It was used to protect infant industries at the founding of the United States as we struggled to build a diverse economy after the Revolution. It later became one of the major reasons contributing to the Civil War as it raised the price on manufactured goods used in the agriculture slave economy of the South but produced in the industrialized North.
Later the enaction of the Smoot-Hawley Tariff in 1929 on imported goods led to other nations doing the same thing to goods they were importing from America. The result was worldwide trade collapsed leading to one of the major causes of the great depression that lasted twelve years. To deal with issues like this most trading nations are members of the World Trade Organization which is supposed to resolve trade disputes dealing with unrealistic pricing of goods being traded.
I was discussing this with a colleague of mine who was in his 30s and he said this was why we need old geezers around to remind others what happened when similar ideas were implemented years ago. My response was that people like that are too old to be relevant today. Their time has come and gone.