Born on his father's plantation, Shadwell, in Albemarle County, Virginia, he graduated from the College of William and Mary and was admitted to the Bar in 1767. Two years later he was elected to the Virginia House of Burgesses, where he joined the Revolutionary Party. He played a prominent part in the calling of the first Continental Congress in 1774, to which he was sent as a delegate, drafting the Declaration of Independence (signed 4 July 1776). He helped to form the Virginia state constitution, and became Governor of Virginia (1779-81).
As a member of Congress in 1783 he secured the adoption of the decimal system of coinage. He was sent to France in 1784 with Benjamin Franklin and Samuel Adams as plenipotentiary, and succeeded Franklin as Minister in 1785. In 1789 George Washington appointed him Secretary of State. As leader of the Democratic-Republican Party, he advocated limited government and envisioned the USA as a republic of independent farmers, and he clashed repeatedly with Alexander Hamilton and the Federalist Party.
After running second in the presidential election of 1796, he became Vice-President (1797-1801) under John Adams, playing little part in an administration dominated by Federalists and drafting the Kentucky Resolves of 1798 to protest the passage of the Alien and Sedition acts. A tie with Aaron Burr in the electoral college threw the election of 1800 into the House of Representatives, where Jefferson was chosen as President, taking office in 1801. The popular vote re-elected him by a large majority for the next presidential term.
Among the chief events of his first term were the war with Tripoli, which subdued the Barbary pirates, and the Louisiana Purchase of 1803, which Jefferson sponsored, setting aside for once his insistence on a strict construction of the Constitution. He also planned the Lewis and Clark expedition to explore the lands to the west of the Mississippi.
His second term saw the firing on the USS Chesapeake by HMS Leopard, the Embargo Act of 1807, the trial of Aaron Burr for treason, and the prohibition of the slave import trade (1808).
In 1809 he retired to his Virginian estate, Monticello, and devoted much time to founding the University of Virginia and designing its campus. A man of letters as well as a gifted architect, he published several books of which the most valuable is his Notes on Virginia (1785), and in old age carried on a famous correspondence with his former political rival John Adams. He and Adams both died on 4 July 1826, the 50th anniversary of the Declaration of Independence.