Joel Roberts Poinsett was an American physician, diplomat and botanist. He was the first U.S. agent in South America, a member of the South Carolina legislature and the United States House of Representatives, the first United States Minister to Mexico, a Unionist leader in South Carolina during the Nullification Crisis, Secretary of War under Martin Van Buren, and a co-founder of the National Institute for the Promotion of Science and the Useful Arts.

The nullification crisis was a sectional political crisis in the United States in 1832 and 1833, during the presidency of Andrew Jackson, which involved a confrontation between the state of South Carolina and the federal government. It ensued after South Carolina declared the federal Tariffs of 1828 and 1832 unconstitutional and therefore null and void within the sovereign boundaries of the state. However, courts at the state and federal level, including the U.S. Supreme Court, repeatedly have rejected the theory of nullification by states.