Thomas Jefferson (1743- 1826) was the third president of the United States (1801-1809). An American Founding Father, he was the principal author of the Declaration of Independence (1776).
President Jefferson made the Louisiana Purchase in 1803, adding vast lands to the United States, including what is now Oklahoma. During his presidency he doubled the size of the United States. President Jefferson sent out the Lewis and Clark Expedition (1804–1806), and later three others, to explore the new west. In 1803, President Jefferson began the process of Indian tribal removal and relocation to the Louisiana Territory west of the Mississippi River, opening lands for eventual American settlers. In 1807 Jefferson drafted and signed into law a bill that banned slave importation into the United States..
President Thomas Jefferson spoke five languages and was deeply interested in the arts, science, invention, architechture, religion and philosophy. He died on July 4, 1826.