The Lewis and Clark Expedition

Jason Gass
Last Updated: February 27th, 2023

In American history, there are few feats of man that are as storied as the Lewis and Clark Expedition. This three-year journey opened up North America from the continental interior to the Pacific Ocean. 

The Lewis and Clark Expedition is also an important part of the history of Montana. The Expedition crossed through Montana following the Missouri and Columbia Rivers on their way to the Pacific Ocean.

In 1803, President Thomas Jefferson desired to have the brightest and most motivated men exploring parts of this growing country that had not been seen by the eyes of many Americans or Europeans. 

President Jefferson knew that the uncharted West was full of unknown discoveries, and with $2,500 in federal funds he put in motion one of the most important exploratory adventures in U.S. history.

The men put in charge of charting the unknown of the Americas were Meriwether Lewis and William Clark; two men already decorated for their services to the young United States. Their journey and the path they took would be etched into American History as the Lewis and Clark Expedition.

Though this trek occurred over 200 hundred years ago, it still sparks imagination in the curious and those with a passion for adventure and finding new places.

An Overview of The Lewis and Clark Expedition

lewis and clarks' winter camp
Image: Don Graham

Following the Louisiana Purchase of 1803, President Thomas Jefferson declared that it was vital to the development and well-being of the new United States to explore the areas along the Missouri and Columbia Rivers. 

These areas, part of the 828,000 square miles within the territory of the Louisiana Purchase, were essential to connecting the continental interior of the United States to the Pacific Ocean. 

With President Jefferson’s vision, planning, and organization a federally funded, expeditionary group, come to be known as the Corps of Discovery was established. The Corps of Discovery would travel from the Mississippi River west in search of a direct route by boat to the Pacific Ocean. 

Along the way, they would discover new people, plants, and animals never seen before. And they would chart the most direct route, though not entirely by water, from the Mississippi River to the west coast of North America.

Headed by Meriweather Lewis and William Clark (for whom the expedition is named), the Corps of Discovery would spend two years trekking across North America, charting new ground, and making substantial contributions to science, cartography, and ethnography. 

The journals of the expedition are still some of the most valuable records of the geography, plants and animals, and peoples of the western United States.

Who was Involved in the Lewis and Clark Expedition?

sacajawea, lewis, and clark
Image: Nathan Borror

While we know much of the two namesakes of the Lewis and Clark Expedition – Meriwether Lewis, and William Clark, they were not the only notable individuals that made the three-year journey across North America.

In 1804, President Thomas Jefferson handed to Meriwether Lewis, his personal secretary, and a trusted advisor, the task of exploring lands within the Louisiana Purchase and west to the Pacific Ocean. 

Lewis started assembling his band of traveling companions, starting with his co-commander, William Clark. Clark had been Meriwether’s military superior during the US government’s battles for land with the Northwest Indian Federation during the early 1790s.

These two men were not the only participants of note. The Corps of Discovery is believed to have as many as 45 members including military enlisted men, military officers, and civilians. 

A few notable individuals who traveled with Lewis and Clark include a black slave named York, a French trapper, a kidnapped Shoshone Indian, and a Newfoundland dog.

Meriwether Lewis, the leader of the Corps of Discovery, was a member of the Virginia state militia. He joined the militia following his graduation from college in 1793. He was part of the militia during the fall of the Whiskey Rebellion, and soon after was promoted to the rank of captain in the U.S. Army. He became the personal secretary to President Jefferson when he was only 27 years old.

William Clark was a member of the Kentucky state militia from the age of 19, and then joined the U.S. Army, where he served with Meriwether Lewis and was later commissioned by President George Washington to be a lieutenant in the Army infantry.

After his service in the Army, Clark returned home in 1796 to manage the family estate. It was seven years later that Lewis would call on his military superior to join him on an epic journey.

Joining the journey from the very beginning was Clark’s trusted slave, a man named York. York, a 30-ish year old man, volunteered for the Corps of Discovery, eager to join in the adventure. York was an invaluable member of the expedition. 

His hunting skills frequently saved the expedition when food was scarce, and he often cared for members of the Corps who had fallen ill or were injured. Additionally, his communication skills allowed him to be a moderator between the expedition and Native American tribal leaders.

York was also instrumental in describing new plant and animal species that were discovered during the expedition.

Not known for his time or contributions to the expedition was Sergeant Charles Floyd. Sergeant Floyd was a member of the team for only three months. Shortly before crossing the Missouri River near Camp Dubois, Floyd died from acute appendicitis. 

Despite the many perils that the Expedition encountered during their three-year journey, Sergeant Floyd was the only member to die. The Floyd River and Floyd Bluffs in northwestern Iowa are named after Sergeant Floyd. 

French-Canadian trapper and trader Toussaint Charbonneau joined the Corps of Discovery in November 1804. He was recruited to the Expedition to be a translator for the Corps. Charbonneau was able to speak French and Hidatsa, which was helpful when dealing with fur traders in areas along the Canadian border, including North Dakota and Montana

Charbonneau’s wife of note (he had two wives) was a Shoshone woman named Sacagawea. Sacagawea was kidnapped from her tribe by the Hidatsa. Charbonneau is believed to have “won” Sacagawea from the Hidatsa. While her inclusion to the Expedition was as Charbonneau’s wife, she quickly became a valuable member of the Corps of Discovery. 

Sacagawea was knowledgeable in navigating the area and was often the interpreter and cultural guide for the Expedition when meeting with other Native American Tribes. Furthermore, she was also important in describing the many new plant and animal species that were discovered during the expedition.

Humans were not the only ones that traveled with the Corps of Discovery that were notable to the Lewis and Clark Expedition. There were many animals that were used during the trip to carry supplies and provide companionship and support to the men and women of the Expedition. 

One of these animals was a Newfoundland Dog named Seaman. Seaman was purchased by Lewis specifically for the expedition. This dog was a valued member of the Expedition and was the only animal that completed the entire trip.

Seaman helped members of the Expedition hunt for food and was known for impressing Native Americans who were in awe of his wisdom and obedience. Seaman was also a keen watchdog and patrolled camps at night keeping an eye out for bears and other predators.

The Lewis and Clark Expedition Discoveries Along the Way

lewis and clark expedition discoveries
Image: U.S. Department of Agriculture

One of the primary goals of the Lewis and Clark Expedition was to find a navigable path, using lakes and rivers from the Mississippi River to the Pacific Ocean. Unfortunately, they were not successful in this task, but they did make many significant discoveries along their path to the Pacific Ocean.

One of the most important accomplishments of the Corps of Discovery was the mapping of the territory and creating a presence within the newly purchased area known as the Louisiana Purchase or Louisiana Territory.

This establishment of the U.S. presence in the Louisiana Territory was important for the westward expansion that would follow in the years after the Lewis and Clark Expedition.

One of the other primary goals of the Corps, as determined by President Jefferson was the journaling and description of new plant and animal species, west of the Mississippi River. During the Expedition, the Corps of Discovery collected thousands of plant, seed, animal, and mineral specimens, and described hundreds more. 

These descriptions of the flora and fauna of the western part of the North American continent were the first scientific contributions to the natural history of the western United States. 

Some of the most significant flora and fauna discoveries by the Lewis and Clark Expedition include the Grizzly Bear, bighorn sheep, the coyote, and prairie dogs. Plants discovered and described during the Expedition include the Douglas fir and ponderosa pine, bitterroot, and sagebrush.

Finally, the Expedition worked tirelessly during their three-year adventure to establish diplomatic relationships with the many indigenous tribes that were scattered across the western United States.

What Was the Purpose of The Lewis and Clark Expedition?

president jefferson
Image: soomness

The three-year-long Lewis and Clark Expedition (1804-1806) had two main goals, as directed by President Thomas Jefferson. The first was to explore and establish a presence in the newly acquired Louisiana Territory.

This goal was important to ensure that those living in this area, including indigenous peoples and French and Spanish settlers, were aware of the change in land ownership.

While this first goal was important to President Jefferson, his primary goal for the Corps of Discovery was to find a route from the Mississippi River to the Pacific Ocean that could be traveled entirely by boat.

Since navigation by boat was the primary mode of transporting goods at this time, President Jefferson knew that finding a single, navigable water route across the western United States was the key to westward expansion. 

The most important waterways to be surveyed by the Corps of Discovery were the Missouri and Columbia Rivers, as they were believed to be the most direct routes to the Pacific Northwest.

This new route to the Pacific Northwest was deemed the “Northwest Passage”. Mapping the Northwest Passage across what is now the states of Iowa, South Dakota, North Dakota, Montana, Idaho, and Oregon, was crucial to President Jefferson’s other goal for the Expedition – laying claim to the Oregon Territory.

Obtaining the Oregon Territory would open new trade routes with Asia and expand the land area held by the growing United States.

While important, one of the less frequently discussed goals of the Lewis and Clark Expedition was to establish diplomatic relations with the indigenous peoples in the western parts of the new Americas.

While the U.S. Military had tried to establish functional relationships with Native Americans, these encounters often ended in violence and bloodshed. 

President Jefferson hoped that a peaceful party of explorers, scientists, and traders would allow for more peaceful interactions with Native Americans and allow for open lines of communications between the U.S. government and tribal leaders.

Why was The Lewis and Clark Expedition Important?

lewis and clark
Image: Paul Sableman

When the Lewis and Clark Expedition returned to Saint Louis in 1806, they likely didn’t understand the importance of their journey. Lewis and Clark met with President Jefferson at the conclusion of their journey to discuss their findings.

Today, the accomplishments of the Lewis and Clark expedition are considered to be extensive and are incredibly important to the expansion of the United States and to the understanding of the cultures of indigenous peoples in the United States, as well as the natural history of the continent.

While their primary goal was to find the elusive “Northwest Passage”, Lewis and Clark were unable to chart a watercourse from the Mississippi River to the Pacific Ocean. Despite this, they were able to establish passable trade routes across the northwestern United States, increasing the ability for intercontinental trade in goods and furs.

Politically, the Lewis and Clark Expedition was crucial in altering the control of the central portions of North America, especially the Pacific Northwest. Before the Expedition, the U.S. struggled to hold claim to the areas now known as Oregon and Washington.

The Lewis and Clark Expedition strengthened the U.S. claims to these areas through the intercontinental trade routes established by the Corps of Discovery.

Finally, the Lewis and Clark Expedition was one of the most significant scientific explorations of the North American continent. The wealth of knowledge acquired, and the description of hundreds of new species was in many cases the basis of knowledge for plants and animals in the western United States.

Lewis and Clark were the first to describe iconic animal species like the grizzly bear and the mountain goat.

The Expedition was critical to mapping and describing the longitude and latitude of points of interest in the western United States and made strides in the art and science of cartography.

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About The Author

Jason Gass

Jason Gass is a Colorado based freelance writer and blogger whose goal is to share a good cup of coffee and great stories around a campfire with close friends. When he’s not working, he spends most of his time traveling, searching for the best breweries, and road-tripping in his teardrop trailer with his wife, daughter, and two dogs.

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