- Thomas Jefferson (April 13, 1743 - July 4, 1826) is best known for being the guy who wrote the Declaration of Independence. Later, he became the third president (1801 - 1809) of the United States of America and bought Louisiana from Napoleon. He then sent Lewis and Clark out to explore the newly purchased countryside. Jefferson was also known for designing (he was also an architect) the famous estate of Monticello, which served as his home. In fact, he’s probably the closest the U.S. presidency has ever had to an Omnidisciplinary Scientist, having also studied mathematics, philosophy, botany, music, archaeology, and several languages (notably French, Greek, Latin, Anglo-Saxon, and Gaelic). Not to mention he also founded the University of Virginia as he couldn’t find a university that could handle his terrifying intellect, and his 6,500-odd book collection formed the seed of the current Library of Congress (after the original contents of the Library were burned in the War of 1812). To top it all off, the guy invented macaroni and cheese and the swivel chair - quite probably the sort of chair your butt graces right now!