In truth very few Alabamians outside the Black Belt were very much exercized about the tariff. All admitted it to be sectional, partial, and unjust. But the regulation of international commerce seemed to a subsistence farmer in the Alabama hills, to have very little relevance to the prosaic round of his existence. Moreover, some trusted political leaders, including Governor John Murphy and Senator John McKinley, told the electorate that in the long run a tariff would force crop diversification and industrialization on the state, which would be quite a good thing.
Politics and Power in a Slave Society: Alabama, 1800-1860, p 27. This is the only mention of tariffs located in the book, which ends with the Secession Convention.
In nearly five hundred pages recording the debates within the Alabama Secession Convention, the issue of the tariff was mentioned three times. In each instance it was raised in corespondence related to the Convention, not in actual debates.
Stephen F Hale to the Governor of Kentucky, p 376
It is upon this gigantic interest, this peculiar institution of the South, that the Northern States and their people have been waging an unrelenting and fanatical war for the last quarter of a century. An institution with which is bound up, not only the wealth and prosperity of the Southern people, but their very existence as a political community. This war has been waged in every way that human ingenuity, urged on by fanaticism, could suggest. They attack us through their literature, in their schools, from the hustings, in their legislative halls, through the public press, and even their courts of justice forget the purity of their judicial ermine, to strike down the rights of the Southern slave-holder, and over-ride every barrier which the Constitution has erected for his protection; and the sacred desk is desecrated to this unholy crusade against our lives, our property, and the Constitutional rights guaranteed to us by the Compact of our Fathers. During all this time the Southern States have freely conceded to the Northern States, and the people of those States, every right secured to them by the Constitution, and an equal interest in the common Territories of the Government; protected the lives and property of their citizens of every kind, when brought within Southern jurisdiction; enforced through their courts, when necessary, every law of Congress passed for the protection of Northern property, and submitted, ever since the foundation of the Government with scarcely a murmur, to the protection of their shipping, manufacturing and commercial interest, by odious bounties, discriminating tariffs, and unjust navigation-laws, passed by the Federal Government to the prejudice and injury of their own citizens.
Letter of Isham W Garrott and Robert H Smith to the Governor of North Carolina, p 435 –
The non-slave-holding States, while declaring that we shall not expand, and that thereby we shall be crushed by our slave population, are charging upon us a design to reöpen the African slave trade, and seize upon two or three ineffectual attempts, by Northern vessels, to import Africans into Southern ports, as an evidence of the fact. The charge is a slander upon our people, and a reflection upon their intelligence. There may be, here and there, found an advocate for the measure, as there may in every community be found individual advocates of any heresy; but our people, with almost entire unanimity, would reject the proposition as offensive to their sense of propriety and averse to their interests. They feel no desire to depreciate the value of their own property, nor to demoralize their slaves by throwing among them savages and cannibals. They will look, as heretofore, to the redundant slave population of the more Northern of their associated sister States of the South for such additions to their negroes as their wants may require.
The state of opinion and of conduct in the non-slave-holding States, finds no justification or apology, in any general or special direction of Federal Legislation to their injury. On the contrary, such legislation has been greatly to their advantage and prosperity. The benefits that have been conferred upon them in the shape of tariff laws, navigation laws, fishing bounties, land laws, and internal improvement laws, have been important aids to their material prosperity--a prosperity which is, in fact, to a great extent, the result of burdens upon the agricultural interests of the South.
Letter to Gov A B Moore from Senator C C Clay, Jr., p 451
There is a manifest purpose of the Black Republicans in both Houses of Congress, to use the power they may have, when the Senators and Representatives of the Cotton States leave here, to enact every species of legislation which hate of the South and lust of power and plunder may suggest. Bills extending the districts for the collection of revenue, so as to authorize collections on board of war vessels in view of Southern ports--increasing the Tariff and making it discriminate more against the South--increasing the Army and Navy--calling for Volunteers and offering them bounties in land and money--employing the militia--authorizing loans and issuing Treasury notes--indeed, every bill will be passed which they can pass, and may deem necessary to strengthen the arm of Government, and to enable Mr. Lincoln to enforce payment of revenue at Southern ports or to blockade them, or to commence war upon the South, as soon as he is installed in office. Such legislation might, probably, be defeated, if the delegates from the Cotton States, about to secede, remained in their seats till the 4th March; and a new Congress could not be convened before September next, by which time we might be fully prepared for war and strengthened by the alliance of all the slaveholding States.
History and Debates of the Convention of the People of Alabama, Begun and Held in the City of Montgomery, on the Seventh Day of January, 1861,
in which is Preserved the Speeches of the Secret Sessions, and Many Valuable State Papers.
WILLIAM R. SMITH
In other words, the tariff represents a tangent to central issues. It is well off base as the cause, or even one of the main causes leading to secession. Tariffs impacted the wealthiest slaveholders and plantation owners (and many Southern political leaders). The tariff had little meaning to the average Southerner who had no need to purchase imported manufactures from Europe or elsewhere outside the United States.