By: Frank Merritt , Pub. 1950, Reprinted 2016, 214 pages, Index, ISBN #0-89308-904-4. Carter County was formed in 1796 by the General Assembly of North Carolina. It was created out of the eastern part of Washington County, an early county originally formed in 1777. The Watauga Settlement was located in present day Carter County. At the time of the creation, its eastern boundary was the North Carolina line, its northwestern boundary was Sullivan County, TN.; and its northern boundary was Washington County, VA.