The Lewis and Clark Trust’s research brings the national scope of the Lewis and Clark Story and Expedition into full view, a nexus of history and geography. Through the compilation of print and digital resources, the first United States military exploration of the American West is presented in chronological order.
Planning, equipping, escorting Sovereign Nation Tribal Chiefs, reporting to President Jefferson, and the Lewis and Clark Journal printing are all in the fabric of the Lewis and Clark Story. The referenced sources explain how the labors of the men and women of the Expedition are still guide posts for all people and ages.
The theoretical Northwest Passage and foreign financial rivalry was never far from Thomas Jefferson’s mind. The first successful military exploration of the West by Lewis and Clark is clearly founded in planning, preparation, and recruitment of people with the “right stuff.” The exploration included recording the findings and experiences as outlined in President Jefferson’s Instructions to Meriwether Lewis.
Phase 1: Planning and Equipping for Exploration
January 18 – July 4, 1803
In 1803, President Thomas Jefferson was no longer just providing verbal support with small amounts of finance for exploration of Western America. The publication and public knowledge of Alexander Mackenzie’s trans-continental crossing of Canada in 1789-1793 became the catalyst that brought the President to action. Using commerce as the primary reason to secure funding from Congress on 18 January 1803, planning for the expedition was fully underway.
While members of the Jefferson Administration were securing maps and passports for the foreign lands to be crossed, Lewis traveled to the U.S. Arsenal at Harpers Ferry to secure rifles, knives, and tomahawks. Much of his time at Harpers Ferry was spent superintending the construction of an iron frame boat.
Jefferson arranged with the leading scholars and scientists in Philadelphia to provide a “crash course” for skills that Lewis would need. In Philadelphia, he was tutored by Robert Patterson (mathematics), Benjamin Smith Barton (botany), Caspar Wistar (paleontology), and Benjamin Rush (medicine). During his “idle time” Lewis secured supplies at the Schuylkill Arsenal and purchased material including $696.00 in “Indian presents.”
On June 19, Lewis wrote to his friend and former Army officer William Clark. This was the most important decision made during the planning. The combined strengths of the two men made the expedition successful. Clark’s response, dated July 18, 1803, was a firm “yes.” With President Jefferson’s Instructions to Lewis dated June 20, 1803, and a Letter of Credit signed July 4th, Lewis left the White House on July 5th for a 28-month expedition across the North American continent.
Explore Phase 1: Journal entries, key figures, weapons & more
Phase 2: Down the Ohio and Up the Missouri
July 5, 1803 – May 14, 1804
Lewis traveled from Washington to Harpers Ferry and Pittsburgh, where frustrating delays with the keelboat builder tested his patience. Finally departing Pittsburgh on August 31, 1803, Lewis navigated the low waters of the Ohio River, recruiting men at military posts along the way.
At Cincinnati, Lewis made a side trip to Big Bone Lick at Jefferson’s request, investigating mastodon bones that had fascinated the President. At the Falls of the Ohio near Louisville, Lewis joined with Clark and they began selecting their final crew. They established Camp Dubois (Camp Wood) near the confluence of the Missouri and Mississippi Rivers, spending the winter of 1803-1804 training and preparing.
On May 14, 1804, the expedition departed Camp Dubois and began their ascent of the Missouri River—the beginning of the greatest exploration in American history.
Explore Phase 2: Journal entries, key figures, wildlife & more
Phase 3: The Westward Journey
May 14, 1804 – November 7, 1805
The Corps of Discovery pushed up the Missouri through present-day Missouri, Kansas, Nebraska, Iowa, and the Dakotas, encountering numerous Native American nations. The expedition’s first loss came on August 20, 1804, when Sergeant Charles Floyd died—the only member to perish during the journey.
Diplomatic councils with the Otoe, Missouri, Yankton Sioux, and Teton Sioux established the pattern of American diplomacy that would shape the West. At the Mandan and Hidatsa villages near present-day Bismarck, North Dakota, they wintered from October 1804 to April 1805, where they met Toussaint Charbonneau and Sacagawea.
In April 1805, the expedition sent the keelboat back with specimens and reports for Jefferson, then pushed into the unknown. They portaged the Great Falls of the Missouri, crossed the Rocky Mountains with Shoshone horses, navigated the treacherous rapids of the Clearwater and Columbia Rivers, and on November 7, 1805, Clark wrote the famous words: “Ocian in view! O! the joy.”
Explore Phase 3: Journal entries, key figures, wildlife & more
Phase 4: Fort Clatsop and the Return
November 1805 – September 23, 1806
The expedition wintered at Fort Clatsop near present-day Astoria, Oregon, enduring a dreary rainy season. In March 1806, they began their return journey, separating into smaller parties to explore more territory. They recrossed the Bitterroot Mountains and reunited at the confluence of the Yellowstone and Missouri Rivers.
Lewis and Clark reached St. Louis at noon on September 23, 1806, ending the Corps of Discovery’s epic adventure of exploration. They had traveled approximately 8,000 miles, documented hundreds of plant and animal species, established relations with dozens of Native American nations, and mapped the way West.
Explore Phase 4: Journal entries, key figures, wildlife & more
Phase 5: After the Expedition
1806 – 1838
The realities of governing the complex Upper Louisiana Territory settled in on the newly appointed Governor Lewis and Brigadier General Clark. Lewis was tasked with publishing the journals while Clark worked to return Sheheke and his family to the Mandan villages.
Lewis’s tragic death on October 11, 1809, along the Natchez Trace remains one of the enduring mysteries of American history. Clark continued as Superintendent of Indian Affairs in St. Louis, ensuring the eventual publication of the expedition journals through Nicholas Biddle in 1814. Clark died on September 1, 1838, in St. Louis, having served his nation for over four decades.
The Lewis and Clark Expedition opened the American West to exploration, settlement, and scientific understanding. Their journals remain the most detailed account of the natural history, geography, and indigenous peoples of the trans-Mississippi West ever compiled, and their legacy continues to inspire new generations of explorers and scholars.
