The Jacana

 Great Lives Site


Back to Jacana

Great Lives index


Lewis and Clark Expedition

Meriwether Lewis and William Clark
1803 – 1806



In 1803, President Thomas Jefferson purchased from France the extensive Louisiana Territory, a vast tract of land comprising nearly two-thirds of the present trans-Mississippi United States. Jefferson was a leading proponent of scientific expansion, a program of planned westward growth that called for the systematic exploration and mapping of new territory prior to settlement. Believing the Louisiana Territory held nearly unlimited potential for the future growth of the United States, Jefferson appointed his personal secretary, a twenty-nine-year-old army captain named Meriwether Lewis, as commander of an expedition to explore the vast region and to locate a water route to the Pacific Ocean. Lewis in turn chose Lieutenant William Clark, a thirty-three-year-old army officer and fellow Virginian, as his co-captain. Late in 1803, Lewis and Clark established their headquarters at St. Louis, where they spent the winter gathering supplies and training the twenty-five soldiers under their command for the arduous journey.

The expedition set out for the unknown in the spring of 1804. Most of the first summer was spent making a difficult ascent up the Missouri River to present-day North Dakota, where the expedition wintered among the villages of the Mandan Sioux. When the expedition moved out the next spring, it was joined by the French-Canadian fur trader and interpreter Toussaint Charbonneau and his Shosone Indian wife, Sacagawea, who emerged as the party's principal guide. With Sacagawea in the lead, carrying her infant son much of the way, Lewis and Clark reached the headwaters of the Missouri and then pushed westward across the Bitterroot Mountains in Montana and Idaho late in the summer of 1805. That autumn the expedition crossed the Continental Divide and descended the Clearwater and Snake Rivers. On 7 November 1805, their canoes reached the mouth of the Columbia River, and the explorers at last laid eyes upon the Pacific Ocean. They built a small wooden post, Fort Clatsop, along the Columbia River as their winter headquarters and embarked upon the return voyage the following March. After recrossing the Rocky Mountains, Lewis and Clark divided the expedition into three groups to map more territory and reunited near the convergence of the Yellowstone and Missouri Rivers. Finally, after nearly twenty-eight months of exploration and travail, the weary expedition arrived to a hero's welcome at St. Louis on 23 September 1806.

In accordance with Jefferson's detailed instructions for the expedition, Lewis and Clark brought back a multitude of scientific information, including maps, the bones and hides from animal specimens, and caged birds and prairie dogs. Of the utmost value were their voluminous journals and diaries, which provided detailed firsthand descriptions of the plant and animal life, geography, and Native peoples encountered during the journey. Although Lewis and Clark failed to locate a convenient water passage to the Pacific Ocean, they were nonetheless handsomely rewarded for their efforts. The U.S. government awarded both men 1,600 acres of land, while each member of the expedition received 320 acres and double pay. Lewis was later appointed governor of the Louisiana Territory, while Clark held a similar post in the Missouri Territory. Their most lasting achievement, however, was their contribution to the opening, both figurative and real, of the American West.


The Meriwether Lewis and William Clark Expedition (1803–1806), headed by Meriwether Lewis and William Clark, was the first American overland expedition to the Pacific coast and back.

Earlier exploration to the Pacific coast

The Lewis and Clark expedition was only the second 'official' transcontinental crossing of North America north of Mexico by a person not of the indigenous peoples of the Americas, having been preceded to the Pacific coast (on July 20, 1793) by a Canadian expedition led by explorer Sir Alexander Mackenzie. Mackenzie had previously crossed North America in 1789 as well, but had turned north at the Continental Divide, also becoming the first European to reach the western Arctic Ocean.

Louisiana Purchase and a western expedition

In 1803, the Louisiana Purchase sparked interest in expansion to the west coast. The United States did not know just what it was buying, and even France was unsure how much land it was selling. A few weeks after the purchase, President Thomas Jefferson, an advocate of western expansion, had Congress appropriate $2,500 for an expedition. In a message to Congress, Jefferson wrote:

"The river Missouri, and Indians inhabiting it, are not as well known as rendered desirable by their connection with the Mississippi, and consequently with us. ... An intelligent officer, with ten or twelve chosen men ... might explore the whole line, even to the Western Ocean ..."

Thomas Jefferson had long thought about such an expedition, but was concerned about the danger. While in France from 1785–1789, he had heard of numerous plans to better explore the Pacific Northwest. In 1785, Jefferson learned that King Louis XVI of France planned to send a mission there, reportedly as a mere scientific expedition. Jefferson found that doubtful, and evidence provided by John Paul Jones confirmed these doubts. In either event, the mission was destroyed by bad weather after leaving Botany Bay in 1788. In 1786 John Ledyard, who had sailed with Captain James Cook to the Pacific Northwest, told Jefferson that he planned to walk across Siberia, ride a Russian fur-trade vessel to cross the ocean, and then walk all the way to the American capital. Since Ledyard was an American, Jefferson hoped he would succeed. Ledyard had made it as far as Siberia when Empress Catherine the Great had him arrested and deported back to Poland.[2]

The American expedition to the Pacific northwest was intended to study the Indian tribes, botany, geology, Western terrain and wildlife in the region, as well as evaluate the potential interference of British and French Canadian hunters and trappers who were already well established in the area.

Jefferson selected Captain Meriwether Lewis to lead the expedition, afterwards known as the Corps of Discovery. In a letter dated June 20, 1803, Jefferson wrote to Lewis

The object of your mission is to explore the Missouri river, and such principal stream of it as by its course and communication with the waters of the Pacific Ocean whether the Columbia, Oregon, Colorado or any other river may offer the most direct and practicable water communication across this continent for the purposes of commerce.[3]

Lewis selected William Clark as his partner. Because of bureaucratic delays in the U.S. Army, Clark officially only held the rank of Second Lieutenant at the time, but Lewis concealed this from the men and shared the leadership of the expedition, always referring to Clark as "Captain".

Route of the expedition

"Left Pittsburgh this day at 11 o'clock with a party of 11 hands 7 of which are soldiers, a pilot and three young men on trial they having proposed to go with me throughout the voyage."[5] With those words, written on August 31, 1803, Meriwether Lewis began his first journal entry on the epic Lewis and Clark Expedition to the Pacific Ocean.

Lewis declared the mouth of the river Dubois (on the east side of the Mississippi across from the mouth of the Missouri river) to be the expedition's official point of departure, but the two and one-half months spent descending the Ohio River can be considered its real beginning.

Clark made most of the preparations, by way of letters to Jefferson. He bought two large buckets and five smaller buckets of salt, a ton of dried pork, and medicines.

The party of 33 included 29 individuals who were active participants in the Corps' organizational development, recruitment and training at its 1803–1804 winter staging area at Camp Dubois, Illinois Territory. They then departed from Camp Dubois, near present day Hartford, Illinois, and began their historic journey on May 14, 1804. They soon met up with Lewis in Saint Charles, Missouri, and the corps followed the Missouri River westward. Soon they passed La Charrette, the last white settlement on the Missouri River. The expedition followed the Missouri through what is now Kansas City, Missouri, and Omaha, Nebraska. On August 20, 1804, the Corps of Discovery suffered its only death when Sergeant Charles Floyd died, apparently from acute appendicitis. He was buried at Floyd's Bluff, near what is now Sioux City, Iowa. During the final week of August, Lewis and Clark had reached the edge of the Great Plains, a place abounding with elk, deer, bison, and beavers. They were also entering Sioux territory.

The first tribe of Sioux they met, the Yankton Sioux, were more peaceful than their neighbours further west along the Missouri River, the Teton Sioux, also known as the Lakota. The Yankton Sioux were disappointed by the gifts they received from Lewis and Clark—five medals—and gave the explorers a warning about the upriver Teton Sioux. The Teton Sioux received their gifts with ill-disguised hostility. One chief demanded a boat from Lewis and Clark as the price to be paid for passage through their territory. As the Indians became more dangerous, Lewis and Clark prepared to fight back. At the last moment before fighting began, the two sides fell back. The Americans quickly continued westward (upriver) until winter stopped them at the Mandan tribe's territory.

In the winter of 1804–05, the party built Fort Mandan, near present-day Washburn, North Dakota. Over the course of the winter the expedition enjoyed generally good relations with the Mandan Indian tribe who lived alongside the Fort. It was at Fort Mandan that Lewis and Clark came to employ a French-Canadian fur trapper named Toussaint Charbonneau, whose young Shoshone Indian wife, Sacagawea, (pronounced Sa-ka-ga-wea) translated for the expedition among the Shoshone and Nez Perce. In a few instances, Sacagawea also managed to serve as a guide for the expedition.
Black-tailed Prairie Dog

In April 1805, some members of the expedition were sent back home from Mandan in the 'return party'. Along with them went a report about what Lewis and Clark had discovered, 108 botanical and zoological specimens (including some living animals), 68 mineral specimens, and Clark's map of the United States. Other specimens were sent back to Jefferson periodically, including a prairie dog which Jefferson received alive in a box.

The expedition continued to follow the Missouri to its headwaters and over the Continental Divide at Lemhi Pass via horses. In canoes, they descended the mountains by the Clearwater River, the Snake River, and the Columbia River, past Celilo Falls and past what is now Portland, Oregon. At this point, Lewis spotted Mount Hood, a mountain known to be very close to the ocean. On a big pine, Clark carved

Clark had written in his journal, "Ocian [sic] in view! O! The Joy!". One journal entry is captioned "Cape Disappointment at the Entrance of the Columbia River into the Great South Sea or Pacific Ocean".[6] By that time the expedition faced its second bitter winter during the trip, so the group decided to vote on whether to camp on the north or south side of the Columbia River. The party agreed to camp on the south side of the river (modern Astoria, Oregon), building Fort Clatsop as their winter quarters. While wintering at the fort, the men prepared for the trip home by boiling salt from the ocean, hunting elk and other wildlife, and interacting with the native tribes. The 1805–06 winter was very rainy, and the men had a hard time finding suitable meat. They never consumed much Pacific salmon because the fish only return to the rivers to spawn in the summer months.

The explorers began their journey home on March 23, 1806. On the way home, Lewis and Clark used four dugout canoes[7] they bought from the Native Americans, plus one that they stole in "retaliation" for a previous theft. Less than a month after leaving Fort Clatsop, they abandoned their canoes because portaging around all the falls proved terribly difficult.
A reenactor describes the bicentennial commemoration of the expedition.

On July 3, after crossing the Continental Divide, the Corps split into two teams so Lewis could explore the Marias River. Lewis' group of four met some Blackfeet Indians. Their meeting was cordial, but during the night, the Blackfeet tried to steal their weapons. In the struggle, two Indians were killed, the only native deaths attributable to the expedition. The group of four: Lewis, Drouillard, and the Field brothers, fled over 100 miles (160 km) in a day before they camped again. Clark, meanwhile, had entered Crow territory. The Crow tribe were known as horse thieves. At night, half of Clark's horses were gone, but not a single Crow was seen. Lewis and Clark stayed separated until they reached the confluence of the Yellowstone and Missouri Rivers on August 11. Clark's team had floated down the rivers in bull boats. While reuniting, one of Clark's hunters, Pierre Cruzatte, blind in one eye and nearsighted in the other, mistook Lewis for an elk and fired, injuring Lewis in the thigh. Once reunited, the Corps was able to return home quickly via the Missouri River. They reached St. Louis on September 23, 1806.

The Corps of Discovery returned with important information about the new United States territory and the people who lived in it, as well as its rivers and mountains, plants and animals. The expedition made a major contribution to mapping the North American continent.


* The U.S. gained an extensive knowledge of the geography of the American West in the form of maps of major rivers and mountain ranges
* Observed and described 178 plants and 122 species and subspecies of animals (see List of species described by the Lewis and Clark Expedition)

* Encouraged Euro-American fur trade in the West
* Opened Euro-American diplomatic relations with the Indians
* Established a precedent for Army exploration of the West
* Strengthened the U.S. claim to Oregon Territory
* Focused U.S. and media attention on the West
* Produced a large body of literature about the West (the Lewis and Clark diaries)











This web page was last updated on: 12 December, 2008