At the behest of President Thomas Jefferson, Captain Meriwether Lewis and Lieutenant William Clark set out on May 14, 1804 with three boats to explore the western land acquired in the Louisiana Purchase. Lewis and Clark traveled up the Missouri river from St. Louis, across the Rocky Mountains, and down the Columbia River to the Pacific Ocean, having to carry their boats on land in spots where the river was too treacherous.
Lewis and Clark returned to Sept. 23, 1806, and received a hero's welcome. They brought back much information in the form of diaries, maps and plant samples. Only one man out of the party of 40 died during the trip, which is extraordinary considering how they endured some hostile Indians, wild animals, and lack of food.
Both were rewarded with large plots of land. Lewis later served as governor of the Louisiana Territory, and Clark governed the Missouri Territory.