The North was in favor of tariffs, while the South hated tariffs. This was because the North was focused on industrialization and the South was focused on agriculture.
A tariff is essentially a tax on foreign goods. It helped protect factories and businesses within the United States, as it made people want to buy from their own country since there was no foreign tax. This was good for the North, as more people were buying their products as opposed to them buying elsewhere. This was not good for the South though, as the South normally sold their goods overseas. This made their products look less desirable to foreign countries, as there was now a tax on them. The South also was buying a lot from overseas, but now it was more expensive.