On September 22, 1804, the Lewis and Clark expedition passed Régis Loisel's abandoned trading post east of here, where around the cedar fort they saw Indian lodges and fallen cottonwoods showing that horses had been feeding on the bark. The next day, three Teton Sioux boys swam to the expedition's campsite and told the captains that a large band of about 80 lodges was camped near the mouth of the next river. The captains gave the boys tobacco and instructed them to tell their chiefs that they would meet the following day in what would be the expedition's first encounter with the Teton Sioux. By 1804, the Sioux Nation dominated the northern Plains and was important enough that President Thomas Jefferson especially wanted a favorable impression made on it. The Sioux Nation had three major divisions, the Santees, the Yanktons, and the Tetons, each speaking a different dialect and calling themselves Dakota, Nakota, or Lakota, all meaning allies. In 1803, Jefferson sent Meriwether Lewis and William Clark to explore the newly acquired Louisiana Territory, seek a route to the Pacific Ocean, and make peaceable contact with native peoples. The expedition left on May 14, 1804, reached the Pacific in November 1805, and returned to Saint Louis on September 23, 1806, after traveling more than 8,000 miles in two years, four months and nine days.