<P> The Neutral Ground (also known as the Neutral Strip, the Neutral Territory, and the No Man's Land of Louisiana; sometimes anachronistically referred to as the Sabine Free State) was a disputed area between Spanish Texas and the United States' newly acquired Louisiana Purchase . Local officers of Spain and the United States agreed to leave the Neutral Ground temporarily outside the jurisdiction of either country . The area, now in western Louisiana, had neutral status from 1806 to 1821 . </P> <P> Spain had been concerned for many years with what it viewed as the encroachment of the French from Louisiana into Texas . About 1734, the French moved their post at Natchitoches from the east to the west side of the Red River . The Spanish governor of Texas, Manuel de Sandoval, was reprimanded for not protesting this violation of what Spain believed was its sovereign territory . In 1740, Governor Prudencio de Orobio y Basterra was ordered to investigate French intrusion in the Natchitoches area . Other investigations were ordered in 1744 and 1751 . </P> <P> In 1753, Texas Governor Jacinto de Barrios y Jáuregui determined that the French had encroached on Texas by occupying territory to the west of Arroyo Hondo, a small creek in western Natchitoches Parish that had previously been used by the French as their western boundary with Texas . In 1764, the boundary dispute became temporarily moot when France ceded its Louisiana colony to Spain . This colony was the large area west of the Mississippi River but drained by the same, plus New Orleans and its immediate vicinity . The transfer was made without resolving the earlier border dispute, which did not seem significant under the circumstances . Spain administered the area from Havana, contracting out governing to people from many nationalities as long as they swore allegiance to Spain and promised to publicly worship in Catholic churches . Many Americans took advantage of these grants that would eventually became known as Rio Hondo claims . </P>

Which river creates a natural boundary for the louisiana purchase of 1803