The South was now a great cotton-producing region. This cotton was grown by negro slaves. The North was now a great manufacturing and commercial region. It was also a great agricultural region. But the labor in the mills, fields, and ships of the North was all free white labor. So the United States was really split into two sections: one devoted to slavery and to a few great staples, as cotton; the other devoted to free white labor and to industries of many kinds.

The South was growing richer all the time; but the North was growing richer a great deal faster than was the South. Calhoun and other Southern men thought that this difference in the rate of progress was due to· the protective system. In 1828 Congress had passed a tariff that was so bad that it was called the Tariff of Abominations. The Southerners could not prevent its passage. But Calhoun wrote an "Exposition" of the constitutional doctrines in the case. This paper was adopted by the legislature ·of Carolina as giving its ideas. In this paper Calhoun declared that the Constitution of the United States was a compact. Each state was a sovereign state and could annul any law passed by Congress. The protective system was unjust and unequal in operation. It would bring "poverty and utter desolation to the South." The tariff act should be annulled by South Carolina and other Southern states.