Present Franklin County was formerly a part of the buffalo hunting range of the Pawnee Indians, whose villages were at one time located further down the valley of the Republican River. Cheyenne and Sioux hunting parties also frequented the area prior to 1869, when Genral Carr's Republican River Expedition cleared the valley of hostiles, opening the region to white settlement.
In September 1870, the Thompson Colony founded Riverton in the eastern part of the county, and the Republican Land and Claim Association or Knight Colony arrived on November 25th, to found the town of Franklin. In the Spring of 1871, a small Negro colony attempted to found a settlement, but their lack of finances forced its abandonment.
By proclamation of Governor Butler, the county was organized on March 3, 1871, with Franklin as the county seat. Nearby Bloomington, site of the U.S. Land Office for the region, won the county seat in 1874, where it remained until 1920. With the arrival of the railroad in 1879, this fertile country was soon settled by homesteaders, many of whose descendants still reside here. Founded during years of depression and natural disaster, Franklin County has a proud heritage.