In 1673, Father Jacques Marquette, a Jesuit missionary, and Louis Joliet, a coureur de bois, led a small French expedition down the Mississippi River from the Illinois country to explore the Mississippi River Valley and find the river's mouth, hoping it flowed west as a route to the Pacific. Near the mouth of the Arkansas River, they encountered the Quapaw, whom they called the Arkansas, and named the river and region after the tribe. After staying several days among the Quapaw and learning that the mouth of the Mississippi was not far to the south, but that strong tribes downriver might kill them, Marquette and Joliet turned back to Illinois. Marquette's report to officials in New France led to a larger French expedition nine years later. In 1682, René-Robert Cavalier, Sieur de La Salle, claimed the Mississippi valley for King Louis XIV of France and named it Louisiana after pausing near present-day Memphis to build Fort Prud'homme and then continuing south to the river's mouth with an expedition of twenty three Frenchmen and thirty one Indians. This venture was less an expansion of empire than an extension of a broad French-Indian trade and military alliance. In 1795, the Spanish established San Fernando de las Barrancas on the Chickasaw Bluffs overlooking the Mississippi River. After the 1797 Treaty of San Lorenzo set the Mississippi as the boundary between Spanish Louisiana and the United States, the United States gained control of the east bank, Spanish garrisons moved across the river, and San Fernando de las Barrancas was relocated to present-day Crittenden County as Campo de la Esperanza, a Spanish naval outpost and defense against Chickasaw raiding. Benjamin Fooy, a Dutchman serving Spanish Louisiana as an Indian agent and interpreter, supervised the new garrison in an area critical to Spanish diplomacy because southeastern Indians used it for trade and hunting in Arkansas and the Mississippi Valley.