The Cherokee Indians sold to the Transylvania Company all of that part of Franklin County which lies south or west of the Kentucky River in 1775. The purchase was made by the company through Daniel Boone as agent. There were no settlements made on that side of the river until about 1784.
Franklin County was created on December 7, 1794 from Woodford, Mercer, and Shelby Counties. Franklin was the 18th Kentucky county in order of formation and was named after the American inventor and statesman Benjamin Franklin. The Kentucky river runs through it from south to north the entire length of the county, dividing it into two nearly equal parts. The three original counties of Kentucky, Jefferson, Fayette and Lincoln, intersected in what is today Franklin County.
Source: The History of Franklin County, Kentucky by L. F. Johnson, pub 1912 and Wikipedia
Owen, Scott, Woodford, Anderson, Shelby and Henry counties.