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.