Short answers, pulled from the story.
The Nullification crisis occurred when South Carolina declared federal tariffs unconstitutional in 1832 and threatened to nullify them. President Andrew Jackson responded by sending messages to Congress proposing the Force Bill to authorize military enforcement of customs laws.
John C. Calhoun wrote his Exposition and Protest in late 1828 arguing that states had the power to veto federal acts violating the Constitution through democratically elected conventions. He published this report with 5,000 copies distributed across South Carolina without identifying himself as author initially.
South Carolina adopted the Ordinance of Nullification on the 24th of November 1832 declaring tariffs unconstitutional after the 1st of February 1833. Governor Hayne established military preparations including 2,000 mounted minutemen and 25,000 infantry troops armed with $100,000 in weapons purchased in the North.
Congress passed both measures simultaneously on the 1st of March 1833 ending the crisis. Henry Clay introduced a negotiated tariff bill on the 12th of February 1833 which reduced rates above 20% by one-tenth every two years until reaching 20% in 1842 while South Carolina repealed its November Ordinance nullifying federal tariffs on March 11.
President Andrew Jackson opposed John C. Calhoun's nullification doctrine because he believed it threatened the preservation of the Federal Union during Senate debates between Hayne and Webster beginning in early 1830. Jackson later told a visitor from South Carolina that if nullification occurred he would hang Calhoun personally leading to Calhoun resigning from office on the 28th of December 1832.