Joel Roberts Poinsett (March 2, 1779 - December 12, 1851) was a physician, botanist and American statesman. He was a member of the United States House of Representatives, the first United States Ambassador to Mexico, a U.S. Secretary of War under Martin Van Buren and a cofounder of National Institute for the Promotion of Science and the Useful Arts, (a predecessor of the Smithsonian Institution), as well as the namesake of Poinsett County, Arkansas and the poinsettia, a popular Christmas flower.
Born in 1779 in Charleston, South Carolina to Dr. Elisha Poinsett and his wife Ann Richards, he was educated in Connecticut and Europe, gaining expertise in medicine and the law. He served as a "special agent" to South American countries from 1810 to 1814 (he was sent there by President James Madison in 1809 to investigate the prospects of the revolutionists, in their struggle for independence from Spain), and returned to his home state of South Carolina in 1815. He ran for office there and served in the South Carolina state legislature from 1816 to 1820 as well as the S.C. Board of Public Works from 1818 to 1820. From 1821 to 1826 he represented South Carolina in the lower house of the United States Congress. He simultaneously served as a special envoy to Mexico from 1822 to 1823 and was appointed the first American minister to Mexico in 1825, and became embroiled in the country’s political turmoil until his recall in 1830. It was during this time that he visited the area of southern Mexico called Taxco del Alarcon and discovered what was later to become known as the poinsettia. (The Aztecs referred to the winter-blooming plant as cuetlaxochitl; its Latin name is Euphorbia pulcherrima or "the most beautiful Euphorbia.") Poinsett, an avid amateur botanist sent samples of the plant home to the States and by 1836 the plant was most widely known as the "poinsettia."
In 1830, Poinsetta returned to South Carolina to espouse the Unionist cause in nullification quarrels and to again serve in the South Carolina state legislature, from 1830 to 1831. He was occupied thusly until 1833, when he married Mary Izard Pringle.
Poinsett served as Secretary of War from March 7, 1837 to March 5, 1841 and presided over the continuing removal of Indians west of the Mississippi and over the Seminole War; reduced the fragmentation of the Army by concentrating elements at central locations; equipped the light batteries of artillery regiments as authorized by the 1821 army organization act; and again retired to his plantation at Georgetown, South Carolina, in 1841.
He was a cofounder of the National Institute for the Promotion of Science and the Useful Arts in 1840, a group of politicians advocating for the use of the "Smithson bequest" for a national museum that would showcase relics of the country and its leaders, celebrate American technology and document the national resources of North America. The group was defeated in its efforts, as other groups wanted scientists, rather than political leaders, guiding the fortunes of what would become the Smithsonian Institution.