Tariff
A tariff is called an optimal tariff if it's set to maximize the welfare of the country imposing the tariff. It is a tariff derived by the intersection between the "trade indifference curve" of that country and the offer curve of another country. In this case, the welfare of the other country grows worse simultaneously, thus the policy is a kind of "beggar thy neighbor policy". If the offer curve of the other country is a line through the origin point, the original country is in the "condition of a small country", so any tariff worsens the welfare of the original country.
Tariff
The American Civil War (1861-1865) allowed the industrial Northeast to get the high tariffs it wanted. The money was needed to finance the war and war debt, but for the next half-century high tariffs were a policy designed to encourage rapid industrialisation and protect the high American wage rates. The Democrats called for low tariffs help poor consumers, but they always failed until 1913. The Republican Party, which is heir to the Whigs, makes protectionism a central theme in its electoral platforms. According to the party, it is right to favour domestic producers and tax foreigners and consumers of imported luxury products. Republicans prioritize the protection function, while the need to provide revenue to the federal budget is only a secondary objective.