Tryon County was formed in 1768 from the part of Mecklenburg County west of the Catawba River, though the legislative act that created it did not become effective until 10 April 1769. It was named for William Tryon, Governor of North Carolina from 1765 to 1771. In 1779 Tryon County was divided into Lincoln County and Rutherford County, and ceased to exist. Tryon County records were transferred to Lincoln County when Tryon was dissolved.
Tryon County played an important early role in the American Revolution. Residents of the county actively organized into committees of safety and later a county militia to prepare against the British following the Battle of Lexington in Massachusetts. On 14 August 1775, 49 Tryon residents gathered at the county courthouse and issued a declaration of grievances against the British known as the Tryon Resolves. They were among the earliest colonists to do so.