Thomas Jefferson’s presidency refers to his time as the third President of the United States from 1801 to 1809, during which he emphasized limited government, individual liberties, and the agrarian ideal. His administration marked a significant shift in American politics as it saw the emergence of the Democratic-Republican Party, which opposed the Federalists and advocated for states' rights and a strict interpretation of the Constitution. Jefferson's presidency is often noted for its focus on expanding the nation through the Louisiana Purchase and promoting an agrarian economy.