First, there is a section in the FAQ of this sub that deals with the causes of the Civil War.

Second, I wrote up this lengthy answer to some questions about secessionists' arguments leading up to the Civil War. Hopefully, that is thorough enough to show how pervasive slavery was when discussing secession and the cause for war.

For tariff specifically, the tariff that was in force at the time of the Civil War was the Tariff of 1857. This replaced the Walker Tariff of 1846. The Tariff of 1857 did not increase the tariff rate. It brought the rate down. It was considered more fair to all people, both in the North and South. There was never any debate in any of the Secession Conventions about the tariff, nor any speeches by secessionists or anyone else about the tariff at the time that the causes for the Civil War were being discussed.

Kenneth M. Stampp writes in his book America in 1857: A Nation on the Brink (Oxford University Press) about the tariff:

"Passage of the Tariff of 1857 was possible because it did not represent a victory of one section over the other; nor did it produce a clear division between parties. Its supporters included Democrats, Republicans, and Americans; representatives of northern merchants, manufacturers, and railroad interests; and spokesmen for southern farmers and planters. Opposition came largely from two economic groups: the iron manufacturers of Pennsylvania and the wool growers of New England and the West."

In other words, the tariff that was in place at the outbreak of secession was a bipartisan bill. Nobody ever seriously discussed it as a cause for war or secession. One delegate to South Carolina's Secession Convention complained about federal taxation in general, but nothing about any specific tariff, and it was not cited in South Carolina's Declaration of Causes. South Carolina was the only state where federal tariffs in general were popular on principle (dating back to the Nullification Crisis of the 1830s). Everywhere else, including all the seceding states, federal tariffs were a matter of national necessity.

The most that can be said was that the Southern Democrat "fire-eaters" were against tariff funds being used for specific purposes by the federal government. Those specifics were, Democrats in general believed that the federal government should not be using funds to build some types of "internal improvements", i.e., infrastructure projects such as the building of railroads, bridges, post offices, etc. This should be left to the states. The only types of infrastructure that tariffs should fund were those of national and international concern, such as the building of harbors (international seaports) and improvements to river navigation. This is addressed in Article I Section 8 Clause 3 of the Confederate Constitution.

However, emphatically, this had nothing to do with a "sectional" North/South divide. This was a divide between Democrats and Whigs, and the Republicans had adopted the Whig philosophy. These "internal improvements" were central to the Whig philosophy known as "the American Systehm". But, since the Confederacy was controlled almost entirely by Southern Democrats, they were able to outlaw some types of use of tariff funds at the national level. Before the war, there had been plenty of Southern Whigs, who generally became Constitutional Unionists, so their voices at the outset of the war were minimized and did not push back.

Regardless, this was a national, partisan issue that was never cited as a cause for war, so I wouldn't even bring it up if someone is challenging you about tariffs. Simply outline the change from the Walker Tariff of 1846, to the bipartisan enactment of the Tariff of 1857. The Walker Tariff had set a tariff rate at 25%. The Tariff of 1857 reduced the rate to between 15-24%.

During the Secession Crisis, there was a new tariff discussed, which was passed in the last days of the Buchanan Administration, known as the Morrill Tariff. However, by the time this was even brought up, secession had already begun. By the time it was passed, seven states had already seceded.