Woodland peoples constructed the first mounds. Rapid civilizational development occurred during the Mississippian period, when Indigenous peoples developed organized chiefdoms and constructed numerous ceremonial structures throughout the state. Spanish conquistadors who explored the region in the 16th century encountered some of the Mississippian peoples, including the Muscogee Creek, Yuchi, and Shawnee. By the early 18th century, most Natives in Tennessee had disappeared, most likely wiped out by diseases introduced by the Spaniards. The Cherokee began migrating into what is now eastern Tennessee from what is now Virginia in the latter 17th century, possibly to escape expanding European settlement and diseases in the north. They forced the Creek, Yuchi, and Shawnee out of the state in the early 18th century. The Chickasaw remained confined to West Tennessee, and the middle part of the state contained few Native Americans, although both the Cherokee and the Shawnee claimed the region as their hunting ground. Cherokee peoples in Tennessee were known by European settlers as the Overhill Cherokee because they lived west of the Blue Ridge Mountains. Overhill settlements grew along the rivers in East Tennessee in the early 18th century. Exploration and colonization The first recorded European expeditions into what is now Tennessee were led by Spanish explorers Hernando de Soto in 1540–1541, Tristan de Luna in 1559, and Juan Pardo in 1566–1567. In 1673, English fur trader Abraham Wood sent an expedition from the Colony of Virginia into Overhill Cherokee territory in modern-day northeastern Tennessee. That same year, a French expedition led by missionary Jacques Marquette and Louis Jolliet explored the Mississippi River and became the first Europeans to map the Mississippi Valley. In 1682, an expedition led by René-Robert Cavelier, Sieur de La Salle constructed Fort Prudhomme on the Chickasaw Bluffs in West Tennessee. By the late 17th century, French traders began to explore the Cumberland River valley, and in 1714, under Charles Charleville's command, established French Lick, a fur trading settlement at the present location of Nashville near the Cumberland River. In 1739, the French constructed Fort Assumption under Jean-Baptiste Le Moyne de Bienville on the Mississippi River at the present location of Memphis, which they used as a base against the Chickasaw during the 1739 Campaign of the Chickasaw Wars. In the 1750s and 1760s, longhunters from Virginia explored much of East and Middle Tennessee. Settlers from the Colony of South Carolina built Fort Loudoun on the Little Tennessee