Later explorers included the French Jacques Marquette and Louis Jolliet in 1673, and Frenchmen Robert La Salle and Henri de Tonti in 1681. Tonti established Arkansas Post at a Quapaw village in 1686, making it the first European settlement in the territory. The early Spanish or French explorers of the state gave it its name, which is probably a phonetic spelling of the Illinois tribe's name for the Quapaw people, who lived downriver from them. The name Arkansas has been pronounced and spelled in a variety of fashions. The region was organized as the Territory of Arkansaw on July 4, 1819, with the territory admitted to the United States as the state of Arkansas on June 15, 1836. The name was historically , , and several other variants. Historically and modernly, the people of Arkansas call themselves either "Arkansans" or "Arkansawyers". In 1881, the Arkansas General Assembly passed Arkansas Code 1-4-105 (official text):