pcr explains tariffs and gives a great history lesson at the same time which clearly states the reason for the war of succession, which wasn't slavery;

US to Impose Tariffs on Canada, Mexico, and China on Feb. 1 and Tyranny on America

Paul Craig Roberts

The US will impose 25 percent tariffs on Mexico and Canada, and 10 percent on China, the Trump White House said.  The purpose of tariffs is to protect domestic manufacturers and their work forces.  What American manufacturers and workers are being protected by Trump’s tariffs?  So much of US manufacturing is located offshore, what purpose are the tariffs serving?

The “tariffs” in reality are taxes imposed on imports of foreign produced goods, including the offshored production of US corporations of goods and services sold in the US.  If the tariffs are paid by the consumer rather than by the US corporations that offshore their production for the American market, the effect will be to reduce the quantity demanded because of the higher price. How much this harms the offshore producers depends on whether their products are price elastic or inelastic. Some are one and some are the other. 

This approach to bringing offshored US jobs back to America is incorrect.  It demonstrates the economic ignorance of Trump and his advisors.  Consider, for example, if US auto assembly relies on parts made in Canada,  a 25% rise in parts cost could shutdown auto assembly and result in US unemployment. As best as I can tell, few auto parts are any longer produced in the US, so there is no industry to protect or to supply the parts that tariffs keep out.  Before you can protect industries, you first must have them.........more.........