John C. Calhoun, in 1827, the year before the 1828 Tariff of Abominations, observed the rising tide of political agitation in the North for tariff protection. He immediately recognized that tariff benefits for the North must come at the expense of the South and that the division would threaten the Union. He believed the tariff, not slavery, was the danger to the Union.

Calhoun was Vice-President of the United States, serving in the administration of President John Quincy Adams. On August 26, 1827, he was at home in South Carolina during the long adjournment between Congresses. On that day, he wrote a long letter to his brother-in-law, Lt. James Edward Colhoun, then serving in the U.S. Navy. aboard the Boston, a sloop of war carrying 24 guns. James was the younger brother of John Calhoun's wife, Floride Colhoun Calhoun.

The first pages of the letter were full of family news. On page 9, however, Calhoun began his explanation to James of the approaching danger to the Union. "The political world," he said, "has assumed a very boisterous appearance, which at the approaching session [of Congress], will probably work up into a storm."

I never have seen such abundant elements of discord, much the greater part of which springs, by an almost necessary consequence, out of the late Presidential election. There is a deep and settled conviction, on the part of a large portion of the Community, not only that Mr. [John Quincy] Adams came in against the publick voice, but that it was effected by a corrupt understanding with Mr. [Henry] Clay.

In the presidential election of 1824, John Quincy Adams had not received the most votes. Andrew Jackson did, but not quite enough to carry the election. Henry Clay was third. The election, as the Constitution required, was thrown into the House of Representatives where Clay presided as Speaker of the House. In the House, a sufficient number of Clay votes went to Adams to elect Adams over Jackson. Adams then appointed Clay Secretary of State. It was called "the Corrupt Bargain." That is the way it was viewed by the Jackson men and many other citizens.

Calhoun perceived that some political observers thought that the administration was attempting to deal with the perception of corrupt bargain by turning to corrupt rewards to appease a northern constituency.

This impression, so weakens the administration, that to sustain themselves, the most dangerous, and corrupt means have been resorted to, as is generally thought. The employment of such has in turn greatly inflamed the publick mind, already deeply agitated by the circumstances attending the election.

Calhoun thought that others in the administration must be resorting to tariff politics that would divide South against North, threatening disunion.

Among the means resorted to,there is one, in particular, that, in my opinion, even threatens danger to the Union, I mean that of arraying the great geographical interest[s] of the Union against one another.

Calhoun touched on the question of the extent to which Congress had the Constitutional authority to raise the tariff for the purpose of encouraging domestic manufactures.

The wisest men of the country, have divided in opinion, how far Congress has the power, or admitting they possess it, how far, on principle, encouragement may be given to domestick manufactures, as connected with the great consideration of the defence and independence of the country.

Calhoun had served in the House of Representatives during the war with Britain in the years 1812 to 1815. After the war, he served as Secretary of War in James Monroe's cabinet from 1817 to 1825. He was keenly aware of the value of having a domestic industry that could manufacture armaments in time of war. He also recognized the utility of tariff protection in fostering that industry. He realized, however, that the tariff was a dangerous tool, for it could make great changes in the business investment of the country and create evil incentives for political expenditures to acquire power.

But whatever may be the diversity of opinion among the wise and patriotick, as to the discreet exercise of this great power of changing the capital, and industry of the country, there cannot among such, be any doubt, that the power itself is highly dangerous; and may be perverted to purposes most unjust and oppressive. Through such an exercise of it, one section of the country may really be made tributary to another; and by this partial action, artful and corrupt politicians may use nearly half of the wealth of the country to buy up partisans, in order to acquire, or retain power. This very use of it, many, and they highly intelligent, below the heads of the Administration are attempting to employ.

Calhoun related some of the recent history of the attempts by the manufacturers to get the tariff on woolens raised and his role in defeating the bill by his tie-breaking vote while presiding over the Senate.

About a year ago, a great excitement was got up in Boston by the capitalists, with a view professedly to give an increase[d] duty on woolens for their protection. A Bill was reported to the House of Rep[resentati]ves amounting in fact to a prohibition, and after much heat passed that body. It came to the Senate, where it was laid on the Table by my casting vote.

After he had killed the woolens tariff bill in early 1827, Congress had adjourned until the next session in December 1827. But disappointed woolen manufacturer and tariff propagandist Lewis Tappan had gotten busy and organized the Harrisburg convention to harness all the manufacturing interests in a unified movement for a tariff. Already now, in the next month after adjournment of the Harrisburg convention, Calhoun recognized the extreme danger in setting up tariff benefits for the North in a scheme that would impoverish the South and split the nation in two.

Since the adjournment, an extensive scheme, originating, as it is thought, with those in power, has been got up to have a general convention of the manufact[ur]ing interest at Harrisburgh [sic], avowedly to devise measures for the passage of this Bill; and thus the dangerous example is set of separate representation, and association of great Geographical interest[s] to promote its prosperity at the expense of other interest[s], unrepresented and fixed in another section, which, of all measures that can be conceived, is calculated to give the greatest opportunity to art, and corruption,and to make two of one nation.

Henry Clay was the great spokesman in Congress for the "American System" of protective tariffs and internal improvements. Since President John Quincy Adams had appointed Clay his Secretary of State, Clay was now part of the administration. Calhoun naturally suspected that Henry Clay was driving the administration to promote the Harrisburg convention.

How far the administration is involved in this profligate scheme,time will determine; but, if they be, the curse of posterity will be on their head.

Calhoun's suspicions about the administration's involvement, however, justified, turned out to be wrong. Henry Clay had little to do with the Harrisburg convention. He was informed of it by some friends by letter while he was at home at his Ashland plantation. He wished them well, of course, but did not otherwise participate. He and others in Congress had prepared the ground, however, in their pro-tariff speeches in Congress that fired up the manufacturers to believe that they deserved the protection of the government from foreign competition.

Calhoun saw southern resentment building against this northern movement for more protective tariffs. James Robert Turnbull had begun to publish in the Charleston Mercury a series of articles, published a few weeks later in October in book form entitled The Crisis: or, Essays on the Usurpations of the Federal Government. Already Calhoun feared southerners might resort to rebellion.

In the mean time, the South has commenced with remonstrating against this unjust and oppress[s]ive attempt to sacrifice their interest; and I do trust, that they will not be provoked to step beyond strict constitutional remedies.

Although the Tariff of Abominations did not become law until May of the next year, Calhoun clearly saw far ahead, that the political machinations were leading to a crisis.

I have given a fuller view on this point, as I am of the impression, that from it great events will spring. It must lead to defeat or oppression or resistance, or the correction of what perhaps is a great defect in our system, that the separate geographical interest[s] are not sufficiently guarded.

Calhoun cautioned James to keep these frankly expressed views confidential.

This for yourself.

This simple letter is, by itself, an effective antidote to the claims by historians that threats to the institution of slavery were tormenting him. The federal Constitution conferred no power on Congress to abolish slavery. That interest was "sufficiently guarded." Calhoun did not mention slavery as a concern.

The tariff interest of the South, however, was the thing "not sufficiently guarded." The Constitution did not prohibit tariffs. The Founders clearly contemplated the tariff as a source of revenue. The mere increase in tariff rates, however, could impoverish the South. But there was no explicit Constitutional protection against an unreasonable rise in tariff rates.

The tariff rate depended solely on the balance of power in Congress to control it. This was the "great defect in our system" that concerned Calhoun.