History :
Sullivan County was formed in 1779 by division from Washington County and named for General John Sullivan, an officer in the Continental Army. On February 7, 1780, the county court was organized at the home of Moses Looney, Sullivan County's first boundaries included Hawkins County, which was broken off from Sullivan in 1786. The county courts met in residences (in the county) including Looney's and Yancey's (near Kingsport) and Cox's, at Thomas Bridge, until 1795. State of Franklin: North Carolina, finding the protection of the western lands difficult, offered them to the United States in 1783, then withdrew the offer. Washington, Sullivan, and Greene Counties organized the State of Franklin in 1784. During this period the people had divided loyalties and operated with two sets of government officials - one North Carolina's - one Franklin's. The State of Franklin collapsed in 1788.

The war between the states found Sullivan County with bitterly divided loyalties. It was the site of much activity with two battles, one in Blountville and one in Kingsport. The railroad, completed in 1859, was the target of many raids and much destruction.

Sullivan County Today: Among the 95 counties in Tennessee, Sullivan is the 6th in population although 55th in land area with 413 square miles. The Federal Census of 2000 was 153,048 persons. It has become one of the most prosperous counties in the South.