Lewis and Clark Expedition

Meriwether Lewis (1774–1809) and William Clark (1770–1838) and their companions were the first white men to cross the western half of the present-day United States.

Jefferson's mission

On January 18, 1803, President Thomas Jefferson (1743–1826; served 1801–9) asked Congress for authorization and funding of $2,500 for an expedition to explore the Missouri River to its source in the Rocky Mountains, and then down the nearest westward-flowing stream to the Pacific. Jefferson gave two purposes for the proposed mission: to prepare the way for the extension of the American fur trade and to advance geographical knowledge of the continent. He particularly wanted to find the most direct water routes across the continent to support trade.

When he sent his message to Congress, none of the territory Jefferson wanted explored belonged to the United States. The area between the Mississippi River and the Rocky Mountains, called Louisiana , belonged to France, and the Pacific Northwest had been claimed by Great Britain, Spain, and Russia, as well as by the United States. But while he was planning the expedition, Jefferson was conducting a negotiation with the French government that resulted in the Louisiana Purchase of 1803. Under this agreement, the United States purchased a huge territory that more than doubled the nation's area. Part of the expedition, therefore, would be on U.S. soil, and part of it would be into areas the United States hoped to acquire.

To command the expedition, Jefferson chose his private secretary, Captain Meriwether Lewis. He, with the president's agreement, invited his old friend William Clark to be the expedition's coleader.

Organizing the corps

After making initial preparations in the East, Lewis traveled to Wood River, Illinois , opposite the mouth of the Missouri River. Clark and several recruits joined him on the way down the Ohio River. Lewis and Clark spent the winter of 1803–4 at Camp Wood River recruiting and training their men, gathering additional supplies and equipment, and collecting information about the Missouri from traders and boatmen. The final, permanent party included twenty-seven young, unmarried soldiers; a half-Indian hunter and interpreter named George Drouillard (c. 1775–1810); and Clark's black slave, York (c. 1770–1831). In addition, a corporal and five privates with several French boatmen were to accompany the expedition during the first season, and then return East with its records and scientific specimens. The expedition was called the Corps of Discovery.

Starting out

The Corps of Discovery began its historic journey on May 14, 1804. It started up the Missouri River in a 55-foot keelboat and two pirogues, or dugout canoes. Averaging about 15 miles a day, by the end of October the Corps of Discovery had reached the villages of the

Mandan and Minnetaree Indians near the mouth of the Knife River in present-day North Dakota . There the explorers built a log fort for winter quarters. During the long, cold winter at Fort Mandan, Lewis and Clark made copious notes in their journals, drew maps of their route, and sought the advice of numerous Indian visitors. From the Minnetarees, especially, they obtained valuable information about the course of the Missouri River and the country through which it ran. These and other Indians contributed enormously to the success of the exploration.

On April 7, 1805, the expedition resumed its journey. The party now numbered only thirty-three persons. It included, besides the permanent detachment, an interpreter named Toussaint Charbonneau (c. 1759–1840) and his young Shoshoni wife Sacagawea (c. 1786–1812). Sacagawea had been captured in an Indian raid and sold to Charbonneau. She was pregnant and gave birth to a baby boy during the journey. Later, Clark adopted the boy.

Uncharted territory

Passing through country never before visited by white men, by August 17 the expedition reached the navigable limits of the Missouri River. With Sacagawea's help, Lewis and Clark purchased horses from Indians who lived nearby and began the portage (getting across the land between two bodies of water with boats and equipment) of the Rocky Mountains. After crossing the mountains, the explorers descended the Clearwater, Snake, and Columbia Rivers to the Pacific, where they arrived in mid-November.

After wintering at Fort Clapsop (named for a neighboring tribe) on the banks of the present-day Lewis and Clark River on the south side of the Columbia River, the explorers started for home on March 23, 1806. They split up temporarily in present-day Montana . Lewis and a small party explored the Marias River, while Clark and the rest of the men descended the Yellowstone River. Reuniting below the mouth of the Yellowstone, they hurried on down the Missouri and arrived in St. Louis, Missouri, on September 23, 1806.

The Lewis and Clark expedition had accomplished its mission with remarkable success. In about twenty-eight months, it had covered more than 8,000 miles. During the entire journey, only one man lost his life, probably from a ruptured appendix. The explorers had met thousands of Native Americans in their travels but had only one violent encounter with them. The total expense of the undertaking was about $40,000. At this small cost, Lewis and Clark and their party took the first giant step in opening the land west of the Mississippi River to the American people.