Fort St. Jean Baptiste State Historic Site or Fort des Natchitoches, in Natchitoches, Louisiana, is a replica of an original French fort settlement; Based on the original fort blueprints, established in 1716 by Sieur Charles Claude Dutisné and company. Natchitoches itself was founded in 1714 by French Canadian Louis Antoine Juchereau de St. Denis as the first permanent European settlement in the territory later known as the Louisiana Purchase. St. Denis would become commandant of Fort St.