John Caldwell Calhoun (March 18, 1782 – March 31, 1850) was the vice president of the United States for John Quincy Adams and Andrew Jackson. Calhoun was vice president under two different presidents. George Clinton is the only other vice president to serve under two presidents. Calhoun's father was an Irish immigrant.
Calhoun is probably best remembered for his strong beliefs in slavery and nullification, which said any US state had the right to reject a federal law if it was unconstitutional. President Andrew Jackson hated nullification and this disagreement started a feud between them. Calhoun was the first vice president in U.S. history to resign from office, doing so on December 28, 1832. In 1844 and 1845 he was United States Secretary of State.