Thomas Jefferson (April 13, 1743 (April 2, 1743 O.S.) – July 4, 1826) was an American Founding Father, the principal author of the Declaration of Independence (1776) and the third President of the United States (1801–1809). At the beginning of the American Revolution, he served in the Continental Congress, representing Virginia and then served as wartime Governor of Virginia (1779–1781). Just after the war ended, from mid-1784 Jefferson served as a diplomat, stationed in Paris, to help negotiate commercial treaties. In May 1785, he became the United States Minister to France. Jefferson was the first United States Secretary of State (1790–1793) serving under President George Washington. Upon resigning his office, with his close friend James Madison he organized the Democratic-Republican Party. Elected Vice-President in 1796, when he came in second to John Adams of the Federalists, Jefferson with Madison secretly wrote the Kentucky and Virginia Resolutions, which attempted to nullify the Alien and Sedition Acts.
Elected president in what Jefferson called the Revolution of 1800, he oversaw a peaceful transition in power, purchased the vast Louisiana Territory from France (1803), and sent the Lewis and Clark Expedition (1804–1806) to explore the new west. His second term was beset with troubles at home, such as the failed treason trial of his former Vice President Aaron Burr, and escalating trouble with Britain. With Britain at war with Napoleon, he tried aggressive economic warfare against them; however, his embargo laws did more damage to American trade and the economy. In 1807, President Jefferson signed into law a bill that banned the importation of slaves into the United States. Jefferson has often been rated in scholarly surveys as one of the greatest U.S. presidents.
A leader in the Enlightenment, Jefferson spoke five languages and was deeply interested in science, invention, architecture, religion and philosophy, interests that led him to the founding of the University of Virginia after his presidency. He designed his own large mansion on a 5,000 acre plantation near Charlottesville, Virginia, which he named Monticello. While not a notable orator, Jefferson was an indefatigable letter writer and corresponded with many influential people in America and Europe.
Jefferson was a tobacco planter and owned hundreds of slaves during his lifetime yet he was opposed to slavery throughout his life and privately struggled with the dilemma of slavery and freedom and its compatibility with the ideals of the American Revolution. Through 1785 Jefferson introduced legislation to end slavery by gradual emancipation and eventual deportation of freed slaves. All the bills were defeated. Under the 1782 Virginia manumission law, Jefferson freed two of his male slaves in 1794 and 1796 respectively.
After Martha Jefferson, his wife of eleven years, died in 1782, Jefferson remained a widower for the rest of his life; his marriage produced six children, with only two surviving to adulthood. In 1802, allegations surfaced that Jefferson was also the father of his slave Sally Hemings' children. In 1998, DNA tests revealed a match between her last child and the Jefferson male family line. Although some historians have noted that the evidence can also support other possible fathers, most have concluded that Jefferson had a long relationship with Hemings and fathered one or more of her children.