John Caldwell Calhoun (March 18, 1782 - March 31, 1850) was a prominent United States politician from South Carolina during the first half of the 19th century. He was the first vice-president born as a United States citizen.
Although he died a decade before the American Civil War broke out between the North and the South, Calhoun was the primary intellectual architect of what would become the short-lived Confederate States of America. Nicknamed the "cast-iron man" for his staunch determination to defend the causes in which he believed, Calhoun pushed the theory of nullification, an extreme states' rights view under which states could declare null and void any federal law they deemed to be unconstitutional. He was an outspoken proponent of the institution of slavery, which he defended as a "positive good" rather than as a necessary evil. His rhetorical defense of slavery was partially responsible for escalating Southern threats of secession in the face of mounting abolitionist sentiment in the North.
This legacy ties Calhoun to the South Carolina-led Southern rebellion against the federal government, but he spent his entire career working for that government in a variety of high offices in Washington, DC. Calhoun served as the seventh Vice President of the United States, first under John Quincy Adams (1825-1829) and then under Andrew Jackson (1829-1832), but resigned the Vice Presidency to enter the United States Senate, where he had more power. He also served in the United States House of Representatives (1810-1817) and was both Secretary of War (1817-1824) and Secretary of State (1844-1845).