Johnson County was created in 1836 from parts of Carter County, Tennessee, where Elizabethton was the county seat. Because it was so difficult for the residents of what is now Johnson County, to travel to Elizabethton, they tried for years to get the county seat moved to a more central location. Their formal petition to move the county seat was rejected by the county, so they petitioned the State to create a new county. Tennessee granted approval for a new county, which was created from some original parts of Carter County and was named after Thomas Johnson, a prominent early settler.