Lewis County is near the northeastern tip of the U.S. state of Kentucky. As of the 2020 census, the population was 13,080. Its county seat is Vanceburg. Kentucky was part of Virginia until 1792. The District of Kentucky began with three counties: Fayette, Jefferson and Lincoln and Fayette. Part of Fayette County was split off as Bourbon County in 17…Lewis County is near the northeastern tip of the U.S. state of Kentucky. As of the 2020 census, the population was 13,080. Its county seat is Vanceburg. Kentucky was part of Virginia until 1792. The District of Kentucky began with three counties: Fayette, Jefferson and Lincoln and Fayette. Part of Fayette County was split off as Bourbon County in 1785; a portion of Bourbon was split off in 1788 as Mason County; in 1806 Lewis County was split off from Mason and named for Meriwether Lewis of the Lewis and Clark Expedition.