In 1828 and 1832 Congress passed what have been called the Tariffs of Abomination, which were a prosperity boon to the North and an economic hardship on the South, especially South Carolina. This led to the Nullification Crisis of 1832 when South Carolina called a state convention and 'nullified' the tariffs as unjust and unconstitutional. The resulting constitutional crisis came very near provoking armed conflict at that time. Through the efforts of former U. S. Vice President and U. S. Senator from South Carolina, John C. Calhoun, a compromise was effected in 1833 which over a few years reduced the tariff back to a normal level of about 15%. Henry Clay and the Whigs were not happy, however, to have been forced into a compromise by Calhoun and South Carolina's Nullification threat. The tariff, however, remained at a level near 15% until 1860.
In May of 1860 the U. S. Congress passed the Morrill Tariff Bill [named for Republican Congressman and steel manufacturer, Justin S. Morrill of Vermont] raising the average tariff from about 15% to 37% with increases to 47% within three years. This was reminiscent and even higher than the Tariffs of Abomination of 1828 and 1832, which had led to a constitutional crisis and threats of secession and armed force. The vote in the U. S. House of Representatives was 105 to 64. Out of 40 Southern Congressmen only one Tennessee Congressman voted for it. High protective tariffs were always the policy of the old Whig Party and had become the policy of the new Republican Party that replaced it.
The Morrill Tariff Act was passed by Congress in 1860, before Lincoln was elected. Lincoln signed the bill into law shortly after taking office in March of 1861.
Williams' contention that the Morrill Tariff prompted South Carolina's secession is correct.
No, actually he is wrong. Had the bill passed in 1860 then it would have been signed by Buchanan not Lincoln, since Lincoln wasn't elected until November. The Morill Tariff did pass the House in 1860 but died in the Senate, blocked by southern senators. It was resubmitted in the next session of Congress and, as Dr. Williams correctly pointed out, finally passed out of the House and Senate in March of 1861 but several months after the seven southern states had seceded.
I think Scruggs has his date wrong. All the information I have indicatesthe Morrill Tariff was passed as soon as Congress returned to session in 1861, not 1860.
In any case, if it were 1860 as Scruggs suggests, one would expect South Carolina to have seceded then, rather than waiting until the end of the year.
The triggering event was Lincoln's election. And Lincoln represented everything the Deep South opposed - not just on tariffs or internal improvements, but also the extension of slavery to the territories. To the extent that Lincoln favored the high tariffs that would have damaged the South's agrarian economy, they had rational grounds to hold such opposition. The real question is whether they were right to take their ball and go home as soon as they lost their first election.