Being admitted to the bar he began practice; in 1808 was elected to the Legislature, and in 1811 to Congress. The war party had gained complete control of the House, and a speaker was chosen by the Democratic party. Calhoun was placed on the Committee of Foreign Relations, and he framed the report that the time had come to choose between tame submission and bold resistance. Calhoun was chosen chairman of this committee, and was a staunch supporter of the administration throughout. The increasing financial distress led to the National Bank debates, in which he was a leading figure. The necessity of this institution being admitted, to Calhoun was intrusted entire management of the bill, and to him is due the passage of the charter of the bank.

He was a most efficient agent of internal improvements, carrying a bill through the House by a vote of 86 to 84, authorizing a million and a half to be paid by the United States bank and the income on seven millions more to be devoted to internal improvements. This bill passed the Senate twenty to fifteen, but was vetoed by the president, denying the authority of congress to appropriate money for any such purpose. He next became Secretary of War, under Monroe. He found the war department in a demoralized condition—bills to the amount of $50,000 outstanding. These Calhoun promptly settled and secured the passage of a bill reorganizing the staff of the army. President Monroe bringing before the cabinet the question of whether he should sign the Missouri Compromise, Calhoun gave it as his opinion that it was constitutional, supporting the view that it was the duty of the president to sign the bill.

He was very seriously thought of as Monroe's successor, the great State of Pennsylvania supporting him at first, but General Jackson's great military fame won for him the nomination, and Calhoun was almost unanimously selected for vice-president.

The tariff question was an all-absorbing issue, and on this question the Democrats divided—the northern wing being for protection, under the lead of Martin Van Buren; while the South was unanimous for free trade, led by Calhoun. A rupture between the president and Mr. Calhoun now arose; this and other causes led to Mr. Calhoun's distrust of the president, and the belief that he could not be depended upon to settle the tariff question; therefore he brought out his nullification doctrine.

This doctrine was founded on the Virginia and Kentucky resolutions of 1798-9 which declared the constitution to be a compact, each State forming an integral part. It also declared that the government created by the compact was not made the final judge, each party having a right to ratify or annul that judgment as an individual State, that is, such laws as were deemed unconstitutional. This doctrine he prepared, and the paper was presented to the legislature where it became known as the South Carolina Exposition. The next we see of it is in the Senate of the United States, where the doctrine is brought forward by Mr. Hayne, which led to his world-famed debate with Mr. Webster.

Then followed the passage of the tariff bill and the nullification act, whereby South Carolina signified her determination to resist the laws; and the final compromise measure of Henry Clay which happily settled the difficulty at this time. Calhoun was now a senator and soon formed one of the powerful trio in opposition to president Jackson. He characterized Jackson's distribution of the surplus left by the United States bank as an attempt to seize onto the power of Congress and unite, in his own hands, the sword and purse.

He declared that he had placed himself with the minority to serve his gallant State, nor would he turn on his heel if thereby he could be placed at the head of the government. He thought that corruption had taken such a hold of it that any man who attempted reform would not be sustained. The American Anti-slavery Society having sent tracts denunciatory to slavery throughout the South, and as it was believed that such measures had a tendency to incite the slaves to insurrection, Calhoun brought in a bill subjecting to severe punishment any postmaster who should knowingly receive any such matter for distribution in any State which should pass a law prohibiting the circulation of such. The bill failed on a final vote, twenty-five to nineteen.

He maintained that Congress had no jurisdiction over the subject of slavery; that it was a recognized institution; that the inequality of the negro was manifest; that in slavery they held their true position and to change their condition was to place them wholly dependent upon the State for support. Calhoun, believed that the relations between the races was right, morally and politically, and demanded that the institution of slavery be protected.

The bill recommended by Jackson, to restrict the sale of public lands to actual settlers and that in limited quantities, drew from him a most fiery speech. He claimed that the measure was really in the interest of speculators who had loaded themselves with land, and whose interest now was to restrict the sale and thus enhance the price of their ill-gotten domain. He also claimed that people high in office had speculated largely, even some in near relation to the president.

This brought from Jackson a letter that he should either retract his words or bring the matter before Congress as an act of impeachment. The sole power of impeachment lies within the House of Representatives, and, while the senate had previously passed an act denouncing Jackson's methods, yet the House of Representatives was overwhelmingly in his favor, and he must have known that no impeachment could pass this body.