At eighteen he began to prepare for college, under the care of his brother-in-law, a Presbyterian minister. In two years he entered Yale College. When in college he studied hard, and was graduated with high honors. [Sidenote: =A lawyer=] Calhoun studied law diligently for three years, a year and a half of the time in his native state, and a year and a half in Connecticut. He began to practice law in South Carolina, but did not have great success. Perhaps it was because the law was too dry for him, or perhaps because he was soon elected to the legislature of his state. In 1811 he was married, and was elected to Congress--two great events in his life. Henry Clay, as Speaker, immediately put Calhoun on an important committee. He quickly sounded a bugle call to war, declaring that it was the duty of "Congress to call forth the patriotism and resources of the country." [Sidenote: =Works hard for the success of the army=] During the War of 1812 he worked hard in Congress for the success of the American army. After the war he favored a tariff to keep English goods out of the country. [Sidenote: =Secretary of War=] President Monroe made him Secretary of War. He found the office in the utmost confusion, but, by hard and careful work, he left the war office a model for future secretaries. [Illustration: JOHN C. CALHOUN _From a photograph by Matthew B. Brady in the collection of the War Department, Washington, D.C._] [Sidenote: =Twice elected vice-president=] [Sidenote: =Calhoun's "South Carolina Exposition"=] =156. Calhoun Favors Nullification.= He was elected vice-president in 1824, and again in 1828. In the last-named year he wrote a paper called the "South Carolina Exposition." In this letter, and in others that he wrote, he told the people of South Carolina there would always be differences between the North and the South. He said the southern people, using slave labor, would raise more tobacco and cotton than they needed, and that the tariff was hurtful to the South. That the northern people, using free labor, would manufacture all kinds of things, and that the tariff would be helpful to them. This document took the ground that between the North and the South there always would be a conflict of interests. The South was devoted to agriculture, and the North to manufacturing. The South had slave and the North free labor. [Sidenote: =South Carolina passes ordinance of nullification=] Therefore, Calhoun concluded that to protect the South from the North a state has the right to nullify a law of Congress. A state has this right, because the state is above the nation. The states made the Constitution. He believed that nullification was a means of saving the country from secession. South Carolina took the fatal step, and nullified the tariffs. This decision was to take effect February 1, 1833, provided the United States did not do something before that time to lower the tariff. [Sidenote: =Jackson warns South Carolina=]