Answer: With high tariffs, foreign goods were taxed so much that the North did not have to lower prices to compete with them.
Explanation: There was a relationship between the North's support for tariffs and the South's opposition to tariffs. Because the Southern economy was devoted to agriculture, it relied on trade for most of its manufactured goods. Without a tariff on foreign goods, the South could buy products from England or other European countries for a cheap price.
However, the Northern economy of the U.S. was devoted to making manufactured goods, and it could not compete with the prices in Europe. If everyone in the South bought products from Europe, the North could not sell its own products anywhere. Therefore, Northerners supported a high "protectionist" tariff on foreign goods to make foreign trading more expensive, so people in the U.S. would have more reason to simply buy goods from the North. This is why the North supported tariffs while the South opposed them.