The tariff rate in the years before the Civil War was close to its lowest rate in US history and hadn't been much of an issue at all since the early 1840s.
In his speech to the Georgia Secession Convention, Alexander Stephens dismissed the notion that the tariff was an issue:
The next evil that my friend complained of, was the Tariff. Well, let us look at that for a moment. About the time I commenced noticing public matters, this question was agitating the country almost as fearfully as the Slave question now is. In 1832, when I was in college, South Carolina was ready to nullify or secede from the Union on this account. And what have we seen? The tariff no longer distracts the public councils. Reason has triumphed. The present tariff was voted for by Massachusetts and South Carolina. The lion and the lamb lay down together-- every man in the Senate and House from Massachusetts and South Carolina, I think, voted for it, as did my honorable friend himself. And if it be true, to use the figure of speech of my honorable friend, that every man in the North, that works in iron and brass and wood, has his muscle strengthened by the protection of the government, that stimulant was given by his vote, and I believe every other Southern man. So we ought not to complain of that. [Mr. Toombs: That tariff lessened the duties.]Yes, and Massachusetts, with unanimity, voted with the South to lessen them, and they were made just as low as Southern men asked them to be, and those are the rates they are now at. If reason and argument, with experience, produced such changes in the sentiments of Massachusetts from 1832 to 1857, on the subject of the tariff, may not like changes be effected there by the same means, reason and argument, and appeals to patriotism on the present vexed question? And who can say that by 1875 or 1890, Massachusetts may not vote with South Carolina and Georgia upon all those questions that now distract the country and threaten its peace and existence? I believe in the power and efficiency of truth, in the omnipotence of truth, and its ultimate triumph when properly wielded.
Georgia was not the only State to secede:
It is not at all surprising, such being the character of the Government of the United States, that it should assume to possess power over all the institutions of the country... To make, however, their numerical power available to rule the Union, the North must consolidate their power. It would not be united, on any matter common to the whole Union – in other words, on any constitutional subject – for on such subjects divisions are as likely to exist in the North as in the South. Slavery was strictly a sectional interest. If this could be made the criterion of parties at the North, the North could be united in its power; and thus carry out its measures of sectional ambition, encroachment and aggrandizement. To build up their sectional predominance in the Union, the Constitution must first be abolished by constructions; but that being done, the consolidation of the North, to rule the South, by the tariff and slavery issues, was in the obvious course of things.
The Constitution of the United States was an experiment. The experiment consisted in uniting under one Government, peoples living in different climates, and having different pursuits and institutions. It matters not how carefully the limitations of such a Government be laid down in the Constitution – its success must, at least, depend upon the good faith of the parties to the constitutional compact, in enforcing them. It is not in the power of human language to exclude false inferences, constructions and perversions, in any Constitution; and when vast sectional interests are to be subserved, involving the appropriation of countless millions of money, it has not been the usual experience of mankind, that words on parchments can arrest power. The Constitution of the United States, irrespective of the interposition of the States, rested on the assumption that power would yield to faith – that integrity would be stronger than interest; and that thus, the limitations of the Constitution would be observed. The experiment has been fairly made. The Southern States, from the commencement of the Government, have striven to keep it within the orbit prescribed by the Constitution. The experiment has failed. The whole Constitution, by the constructions of the Northern people, has been absorbed by its preamble. In their reckless lust for power, they seem unable to comprehend that seeming paradox – that the more power is given to the General Government, the weaker it becomes. Its strength consists in the limitation of its agency to objects of common interests to all sections. To extend the scope of its power over sectional or local interests, is to raise up against it opposition and resistance. In all such matters, the General Government must necessarily be a despotism, because all sectional or local interests must ever be represented by a minority in the councils of the General Government – having no power to protect itself against the rule of the majority. The majority, constituted from those who do not represent these sectional or local interests, will control and govern them. A free people cannot submit to such a Government. And the more it enlarges the sphere of its power, the greater must be the dissatisfaction it must produce, and the weaker it must become. On the contrary, the more it abstains from usurped powers, and the more faithfully it adheres to the limitations of the Constitution, the stronger it is made. The Northern people have had neither the wisdom nor the faith to perceive, that to observe the limitations of the Constitution was the only way to its perpetuity.
Under such a Government, there must, of course, be many and endless "irrepressible conflicts," between the two great sections of the Union. The same faithlessness which has abolished the Constitution of the United States, will not fail to carry out the sectional purposes for which it has been abolished. There must be conflict; and the weaker section of the Union can only find peace and liberty in an independence of the North. The repeated efforts made by South Carolina, in a wise conservatism, to arrest the progress of the General Government in its fatal progress to consolidation, have been unsupported, and she has been denounced as faithless to the obligations of the Constitution, by the very men and States, who were destroying it by their usurpations. It is now too late to reform or restore the Government of the United States. All confidence in the North is lost by the South. The faithlessness of the North for half a century, has opened a gulf of separation between the North and the South which no promises nor engagements can fill.
It cannot be believed, that our ancestors would have assented to any union whatever with the people of the North, if the feelings and opinions now existing amongst them, had existed when the Constitution was framed. There was then no tariff – no fanaticism concerning negroes...
- THE ADDRESS OF THE PEOPLE OF SOUTH CAROLINA, ASSEMBLED IN CONVENTION, TO THE PEOPLE OF THE SLAVEHOLDING STATES OF THE UNITED STATES, 1860
(Reminds me, in some ways, of our present state of affairs.)
Tariffs had been an issue for decades, and that simple fact was recognized, in public, in writing, in the 1860s...