Joel Roberts Poinsett, American physician and politician, 15th United States Secretary of War (d. 1851)

Joel Roberts Poinsett (March 2, 1779 – December 12, 1851) was an American physician, diplomat and slave owner. 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 (a predecessor of the Smithsonian Institution).