In 1540, Coronado, the Spanish explorer and governor of Mexico, traveled from Mexico through the southern Great Plains, including this part of Oklahoma, returning via New Mexico. He claimed all of the western United States for his native Spain. French explorers claimed the same area. By 1800 Spain had sold their territorial rights to France. In 1803 France sold the vast territory known as Louisiana to the U.S. for 15 million dollars. Washita County, Oklahoma, was a part of that land.