The expedition of Lewis and Clark

In 1803, when Thomas Jefferson was the President of the United States, the U.S. purchased the Louisiana Territory from France. This was a huge tract of over 800,000 square miles, taking in nearly the entire mid-section of North America. This area included much of what are now the 15 states of Montana, Wyoming, North Dakota, South Dakota, Colorado, Nebraska, Kansas, Minnesota, Iowa, Missouri, New Mexico, Texas, Oklahoma, Arkansas, and Louisiana. This almost doubled the size of the new country.

Much of the new territory was unexplored. Jefferson decided to send an expedition up the Missouri River to its source in the western mountains and beyond to the Pacific Ocean. Jefferson hoped that the expedition would be able to find the elusive Northwest Passage, a water route across the country, which would be a great boon to commerce, and to map the new Northwest territory, to fill in the empty spaces on the maps of the time.

Jefferson hoped that Lewis and Clark would find a water route across North America. Up to that point, trade with India and the Orient was only possible by sailing south around Africa or South America, a long and arduous journey. For hundreds of years, explorers had searched for a way to cross the continent by a water route, sometimes know as the Northwest Passage or the Passage to India.

So in that same year, Jefferson commissioned the Corps of Discovery under the command of his trusted private secretary, Meriwether Lewis. Besides seeking the Northwest Passage, Lewis was to map the new territory, assess its natural resources, and make contact with its inhabitants, befriending them if possible. Lewis recruited his friend William Clark to share equally in the command of the expedition, as well as a force of over 40 men. The members of the Corps of Discovery were soldiers, but their purpose was peaceful -- exploration, diplomacy, and science. Lewis was commissioned as a Captain of the Army of the United States, Clark as a Lieutenant (although this inferior rank was kept secret from the men, and Clark was always called "Captain").

Lewis purchased a large stock of supplies, including guns and ammunition, food, clothing, navigational instruments, and large numbers of goods to be used as gifts and barter for Indians. To carry the Corps and its cargo on the first leg of their journey, Lewis had a keelboat built, a 55-foot shallow-draft vessel capable of carrying about 12 tons of cargo. The boat had a sail, but was mostly propelled with oars and poles. The journey on the Missouri River would be over 2,000 miles -- upstream all the way.                                                                                                                

Up the Missouri

The expedition started from St. Louis, where the Missouri empties into the Mississippi, on May 14, 1804. Along the way, Clark oversaw the men and carefully mapped the route. Lewis made scientific observations and collected specimens of animals and plants. The party made only 12 or 14 miles on a good day.                 

Along the way, the group made contact with Indian inhabitants of the land. During the first season of travel, they contacted the Missouris, the Omahas, the Yankton Sioux, the Teton Sioux (Lakota), and the Arikaras. The captains would offer gifts, meet with the chiefs, and make speeches encouraging the Indian nations to make peace with one another and with their new "great father," President Jefferson. All were friendly except the Lakota, with whom the expedition had a confrontation that nearly became violent.

By October, Lewis and Clark decided to build a fort and winter with the Mandans and their Hidatsa neighbors. These tribes, with a population of about 4,500 people, occupied five permanent villages along the Missouri River and were known for their friendliness and generosity.