12 Fascinating Tidbits About the Lewis and Clark Expedition

During the summer of 1804, Meriwether Lewis and William Clark set out from St. Louis on an epic 8000-mile trek across North America. Commissioned by President Thomas Jefferson, their Corps of Discovery aimed to explore the western territories acquired from France in the Louisiana Purchase and locate a viable water route to the Pacific.

While they didn’t achieve their primary goal, the expedition returned with invaluable journals filled with observations, detailed maps of unexplored regions, insights into Native American cultures, and evidence to justify the nation's westward expansion. Discover 12 intriguing facts about their journey.

1. The expedition was funded through a covert request by President Thomas Jefferson.

The early 1800s were marked by tense diplomatic dealings between the fledgling United States and European powers. Spain, which controlled Louisiana and New Orleans, had permitted the U.S. to use the Mississippi River for trade without conflict. However, in 1800, France acquired Louisiana from Spain. U.S. leaders grew concerned about Napoleon Bonaparte’s ambitions to revive the French empire at this strategic port, potentially obstructing America’s westward growth. Great Britain also eyed the territory with interest.

Recognizing the political powder keg, Jefferson instructed James Monroe and Robert Livingston, the U.S. envoy to France, to broker a deal for New Orleans with Bonaparte. Simultaneously, Jefferson quietly sought $2500 from Congress (approximately $61,800 today) to fund an expedition aimed at “[expanding] the external commerce of the United States.” The House addressed the matter under “an oath of secrecy” and approved it in February 1803.

Around the same time, the victorious uprising of enslaved people in France’s St. Domingue colony (now Haiti) altered Bonaparte’s strategy. To finance his government, he proposed selling not only New Orleans but also a massive portion of North America—spanning 830,000 square miles—to Monroe and Livingston for $15 million, excluding interest (roughly $371 million today).

2. The Corps of Discovery was charged with locating a water route to the Pacific Ocean.

Jefferson approved the agreement unilaterally; Monroe and Livingston finalized the Louisiana Purchase Treaty on May 2, 1803, in Paris. (The Senate ratified the treaty shortly afterward.)

The acquisition effectively doubled the nation’s size, enabling Jefferson to solidify his vision of westward expansion. After Congress allocated $2500, the president appointed Meriwether Lewis, his 28-year-old personal secretary and a seasoned soldier, to lead the mission. The goal was to foster trade and diplomacy with Native tribes in the newly obtained territories and to identify a viable water passage linking the Mississippi River to the Pacific. Lewis selected William Clark, a 33-year-old militia officer, as his co-leader of the Corps of Discovery.

3. Officially, Lewis held a higher rank than Clark.

Although Lewis had fought alongside Clark in multiple military engagements and held him in high regard, his request to have Clark commissioned as an equal leader was denied by the U.S. secretary of war. Despite this, the two men decided to maintain the illusion of joint leadership. They addressed each other as “captain” to prevent the rest of the team from noticing the hierarchy.

4. Lewis shelled out $20 for the expedition’s canine companion.

During preparations in Pennsylvania, Lewis purchased a Newfoundland dog for $20, which is thought to have accompanied the explorers throughout their entire journey. Historians disagree on the dog’s name, with most contemporary sources calling him Seaman, while others suggest Scannon or Seamon.

In a journal entry from November, Lewis noted that members of the Shawnee and Delaware tribes attempted to trade for the dog. He declined, citing the $20 cost and praising the dog’s “gentle nature and suitability for the expedition.”

Lewis and Clark honored the dog by naming “Seaman’s Creek” in Montana, though the name was never officially recognized. Today, it is called Monture Creek.

5. The Corps of Discovery embarked on their journey where the Missouri and Mississippi rivers meet.

The expedition set off from Camp Wood, located north of St. Louis, in May 1804. Over 40 men joined the venture, including the two co-leaders, a hired boat crew, and individuals (mostly from Virginia and Kentucky) skilled in surveying, blacksmithing, hunting, and other outdoor expertise. Sergeant Charles Floyd was the sole casualty, likely due to a burst appendix. His burial site in Iowa is commemorated with a 100-foot stone obelisk.

6. An enslaved individual accompanied the Corps of Discovery.

In addition to the expedition members, soldiers, and interpreters who joined the team, Clark brought along his “body servant,” an enslaved man named York, whom he had inherited from his father.

York stood as the sole Black member of the Corps of Discovery. He protected the group, hunted—a rare privilege for an enslaved person, as they were typically barred from using firearms—and reportedly participated in decision-making. His presence was pivotal in interactions with Native tribes, many of whom had never encountered a Black man and were fascinated by him.

After the expedition returned east, York requested his freedom as compensation for his two years of service. Clark denied his plea. When York suggested relocating to Louisville, Kentucky, to work as a hired laborer and reunite with his wife, Clark also rejected this proposal.

7. Sacagawea was the lone female member of the expedition.

Sacagawea, the daughter of a Shoshone chief in present-day Idaho, was captured by the Hidatsa, their adversaries, at around age 12. While living with the Hidatsa in what is now North Dakota, she was traded or sold to Toussaint Charbonneau, a French-Canadian trapper residing with the tribe, who took her as one of his wives.

Lewis and Clark encountered Sacagawea, then approximately 17, upon reaching the Hidatsa-Mandan village in November 1804. They hired Charbonneau as an interpreter and included Sacagawea due to her fluency in Shoshone and Hidatsa, which aided in negotiations with tribes they met. She also assisted in identifying edible plants and guiding the group through the Bitterroot Mountains.

The Corps of Discovery constructed Fort Mandan nearby and spent the winter there before resuming their journey in spring 1805—two months after Sacagawea gave birth to her son, Jean Baptiste. Although bringing a newborn on such a demanding expedition might seem impractical, historians believe that having a Native woman and infant among the group helped the corps appear less threatening to the tribes they encountered.

8. Spain attempted to stop and arrest Lewis and Clark.

Spain still controlled vast territories in North America, stretching from modern-day eastern Texas to the Columbia River in the Pacific Northwest. Concerned that Lewis and Clark’s expedition might jeopardize their claims to gold in the Southwest, the Spanish government sought to disrupt their mission. James Wilkinson, a former Revolutionary War general and Spanish spy referred to as Agent Number 13, sent encrypted messages to Spanish leaders, alerting them to the expedition. He advised them to “dispatch a sufficient force to intercept Captain Lewis and his party on the Missouri River, compelling them to retreat or capturing them.” Despite their efforts, Spain failed to locate the expedition.

9. The expedition members occasionally consumed dog meat.

The group loaded their keelboat with seven tons of preserved food items, such as flour, beans, dried pork, sugar, coffee, salt, corn, and lard. They also carried “portable soup,” created by reducing broth to a glue-like consistency and drying it into rubbery chunks that could be rehydrated later. However, protein was often in short supply. The men hunted, fished, and traded with tribes for various meats, which at times included dogs. Fortunately, their Newfoundland dog, Seaman, was spared.

10. The expedition collected 200 plant specimens and documented 122 animal species previously unknown to Western science.

Lewis and Clark meticulously documented their findings in detailed journals. They are recognized for identifying 122 animal species previously unknown to Western science and gathering over 200 plant specimens during their expedition. While Indigenous peoples in the regions they traversed had long been familiar with these plants and animals, Lewis and Clark introduced them to Eastern scholars for the first time.

Their records included descriptions of grizzly bears, prairie dogs—which Lewis suggested naming “barking squirrels”—coyotes, jackrabbits, and pronghorn. Their botanical collections featured bitterroot, ponderosa pine, and Douglas fir. However, they did not encounter a living mastodon, much to Jefferson’s disappointment.

11. The Lewis and Clark expedition spanned over two years.

Lewis and Clark followed the Missouri River and its branches until they reached the Continental Divide in what is now Montana. The Corps traversed the Rocky Mountains on horseback and then followed the Columbia River to the Pacific coast. They endured the rainy winter of 1805-1806 at Fort Clatsop, a structure they constructed near the Columbia River’s mouth, and established friendly relations with the local Native tribes.

In March 1806, they embarked on their return journey to St. Louis. At Lolo Pass in the Rockies, Lewis and Clark divided their group; Lewis and a team retraced their earlier path and explored river systems in northwest Montana, while Clark and his party traveled south and east along the Yellowstone River. They reunited on the Missouri River north of Fort Mandan in North Dakota and continued downstream. On September 23, 1806, they arrived in St. Louis, having journeyed nearly 8000 miles.

12. Lewis passed away three years after the expedition under mysterious circumstances.

Lewis died on the morning of October 11, 1809, at the age of 35. Historians remain divided over whether his death was a suicide or a homicide.

At the time, Lewis was serving as governor of the Upper Louisiana Territory and was traveling along the Natchez Trace, a route stretching from Mississippi to Tennessee. He stopped at an inn operated by the Grinder family, and by morning, he was found dead from gunshot wounds to his head and abdomen.

Most historians, though not all, believe he died by suicide, citing circumstantial evidence: Lewis was known to suffer from depression, drank excessively, and faced financial difficulties. He had reportedly tried to end his life before the trip and had even written a will during his journey.

Others argue he was murdered, casting doubt on Mrs. Grinder’s account; she claimed to have heard gunshots and seen Lewis stumble outside (though she did not assist him). Some speculate that Mr. Grinder or a bandit from the Natchez Trace may have shot him. Regardless of the true cause, Lewis was laid to rest in Hohenwald, Tennessee, where a memorial was later built in his honor.