Jefferson was designated the county seat of Jackson County on November 24, 1806. The city, named for President Thomas Jefferson, was the site of a previous Indian settlement. The site of the city was originally an Indian settlement named Thomocoggan. The city was then incorporated as Jeffersonville. Later, the name was changed to Jeffersonton and finally shortened to its current name on June 30, 1824. Dr. Crawford W. Long first used ether for surgery in Jefferson on March 30, 1842.