John Caldwell Calhoun (pronounced /kælˈhuːn/; March 18, 1782 – March 31, 1850) was a leading politician and political theorist from South Carolina during the first half of the 19th century. A powerful intellect, Calhoun eloquently spoke out on every issue of his day, but often changed positions. Calhoun began his political career as a nationalist and proponent of protective tariffs; later, he switched to states' rights, limited government, nullification and free trade. He is best known for his intense and original defense of slavery as a positive good, for his promotion of minority rights, and for pointing the South toward secession from the Union.
Devoted to the principle of liberty and fearful of corruption, Calhoun built his reputation as a political theorist by his redefinition of republicanism to include approval of slavery and minority rights--with the white South the minority in question. To protect minority rights against majority rule he called for a "concurrent majority" whereby the minority could sometimes block offensive proposals. Increasingly distrustful of democracy, he minimized the role of the Second Party System in South Carolina. Calhoun's defense of slavery became defunct, but his concept of concurrent majority, whereby a minority has the right to object to or perhaps even veto hostile legislation directed against it, has been incorporated into the American value system.
He held every major post except president, serving in the House, Senate and vice presidency, as well as secretary of war and state. He usually affiliated with the Democrats, but flirted with the Whig Party and considered running for the presidency in 1824 and 1844. As a "war hawk" he agitated in Congress for the War of 1812 to defend American honor against Britain. As Secretary of War under President James Monroe he reorganized and modernized the War Department, building powerful permanent bureaucracies that ran the department, as opposed to patronage appointees.