By the Ohio Enabling Act of 1802 settlers in the Whitewater valley became citizens of the Indiana Territory and residents of Clark county, which had been organized from the eastern part of Knox in 1801, with the county seat at Falls of the Ohio, later called Clarksville. On Sept. 30, 1809, the United States, on behalf of the Northwest Territory and Governor William Henry Harrison, concluded the Treaty of Fort Wayne, part of whose terms included the purchase from the Indians of a strip of land locally called "The 12 Mile Purchase" parallel to and west of "The Gore", enclosing the Whitewater Valley and comprising the largest portion of the future county. Conclusion of the treaty essentially ended Indian occupation of the county and cleared the way for settlement. In southeastern Indiana, a part of the Northwest Territory nicknamed "The Gore" was ceded from Ohio to Indiana in 1803 and became Dearborn County. Wayne and Franklin counties were carved from Dearborn and Clark counties in 1811. At that time much of southeastern Indiana was divided between the two latter counties. Fayette County was created by act of the Indiana General Assembly in December 1818 from portions of Wayne and Franklin counties and unincorporated ("New Purchase") territory in the northern portion of the county. It was named for the Marquis de la Fayette, a French hero of the Revolutionary War. Connersville, then a small village of less than a hundred inhabitants, was designated the county seat. The county was divided into five townships (Harrison, Connersville, Jennings, Columbia, and Brownsville) in February 1819, Connersville Township containing the namesake town. In 1821, the organization of Waterloo Township subsumed the portion of Brownsville Township remaining in Fayette County, along with a portion of Harrison Township west of the Whitewater River. The far eastern part of Fayette lying between the Treaty of Greenville treaty line of 1795 and the present eastern boundary line of Waterloo and Jennings townships was split off into the newly created Union County in 1821. In 1826, a small part in the southeastern portion of Jackson township not included in the limits of the county in 1818, being left a part of Franklin county, was attached to Fayette County. Four additional townships were created in later years: Posey (1823), Orange (1822), Jackson (1820) and Fairview (1851), corresponding to settlement of the area. At the time of its organization in 1819, the county had approximately 3,000 residents.