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.
Bluffton Movement
The impetus for the movement was the passing in congress of the Tariff of 1842, a protectionist tariff that enraged southern planters. The tariff raised the amount of dutiable goods as well as the rate of taxation on all goods, and it resulted in a sharp decrease in international trade. That was beneficial to northern industrialists, who no longer had to worry about competition from overseas, but greatly hurt southern planters, who relied on international markets for their products. The inequity of the tariff, in direct contrast to the Compromise of 1833, which lowered the protectionist tariffs for the South, caused massive opposition.