Lewis inherits his father's Virginia plantation and assumes responsibility for more than twenty enslaved people at age 18.

Jefferson recruits Lewis from his army post to serve as his personal secretary at the White House.

Jefferson completes the Louisiana Purchase from Napoleon, doubling the size of the United States.

Jefferson officially selects Lewis to lead an expedition to chart the Louisiana Territory and reach the Pacific.

Lewis meets William Clark in Clarksville and the two men begin formally assembling the Corps of Discovery.

The expedition departs the St. Louis area and heads west up the Missouri River.

A tense standoff with Sioux chiefs nearly turns violent before Chief Black Buffalo forces the other chiefs to stand down.

The expedition winters at Fort Mandan, where Sacagawea and her husband Charbonneau join the crew.

Shoshone chief Cameahwait informs Lewis that no all-water route to the Pacific Ocean exists.

Sacagawea recognizes Shoshone chief Cameahwait as her brother, securing horses and assistance for the mountain crossing.

The expedition reaches and sights the Pacific Ocean after navigating the Columbia River.

Lewis and Clark split the party on the return journey to explore additional territory.

Blackfeet warriors attempt to steal the expedition's rifles, and two warriors are killed in the resulting confrontation.

The expedition arrives back in St. Louis to widespread celebration from citizens who believed them dead.

Lewis dies by suicide at a remote inn in Tennessee while traveling to Washington to defend himself against financial accusations.

Meriwether Lewis, raised on a Virginia plantation and shaped by Jefferson's mentorship, is chosen to lead an ambitious expedition across the newly purchased Louisiana Territory to the Pacific Ocean. After assembling the Corps of Discovery with co-captain William Clark, the expedition pushes up the Missouri River, surviving a dangerous standoff with the Sioux and wintering at Fort Mandan, where Sacagawea joins as an interpreter. The crossing of the Rocky Mountains proves nearly fatal, and the discovery that no all-water route to the Pacific exists dashes Jefferson's central commercial dream. The expedition reaches the Pacific and returns east, but a deadly confrontation with the Blackfeet and Lewis being shot by one of his own men mark the troubled final leg. Celebrated as a hero upon returning to St. Louis, Lewis is appointed governor of Louisiana but spirals into debt, alcoholism, and depression. Unable to navigate political life as he had navigated the wilderness, Lewis dies by suicide on his way to Washington to defend himself against financial accusations.

The headline events of Lewis and Clark's expedition and Lewis's tragic end.

Lewis's father dies and his mother quickly remarries; Lewis learns wilderness survival skills from his frontier mother.

Lewis marches with the Virginia militia raised to suppress the Whiskey Rebellion in western Pennsylvania.

Lewis challenges a superior officer to a duel over political arguments and is transferred to William Clark's rifle company.

Lewis purchases a Newfoundland dog named Seaman while waiting for his expedition boat to be completed.

The expedition witnesses the official transfer of Louisiana territory from Spain through France to the United States in a St. Louis ceremony.

Clark is denied a captain's commission and receives only a lieutenancy; Lewis keeps the demotion secret from the crew.

Lewis delivers a speech to Oto tribe delegates calling Jefferson their new great father and distributing diplomatic gifts.

The white pirogue nearly capsizes in a sudden squall, almost destroying the expedition's navigation tools and handwritten notes.

Lewis and Clark each explore a separate fork of an unexpected new river to determine which branch is the true Missouri.

The Nez Perce privately debate killing the expedition members for their rifles and goods before a Salish woman intervenes.

Lewis and Clark take a vote among the full crew, including York and Sacagawea, to choose the site of their Pacific coast winter camp.

Charbonneau and Sacagawea leave the expedition upon returning to the Mandan villages; Sacagawea receives no payment for her service.

Lewis reports to Jefferson in Washington and both men get down on their knees together to examine Clark's massive map.

Lewis is appointed governor of Upper Louisiana but quickly clashes with political rivals and struggles with administrative duties.

Nicholas Biddle helps Clark publish the expedition journals, and a later scholarly edition by Reuben Gold Thwaites restores Lewis's historical reputation.

Lewis's early life is defined by frontier survival skills learned from his mother and military experience gained during the Whiskey Rebellion, where he first briefly serves alongside William Clark. The practical preparations for the expedition — from acquiring his dog Seaman to witnessing the Louisiana transfer ceremony in St. Louis — reveal how much depended on logistics and political maneuvering before a single mile of wilderness was crossed. Along the Missouri, the expedition's first diplomatic encounter with the Oto tribe exposes the inadequacy of their gift-giving strategy, while near-disasters like the pirogue almost capsizing threaten to end the mission entirely. On the Pacific coast, a democratic vote among the crew — including York and Sacagawea — to choose their winter camp marks an unusual moment of inclusion before the long return. After the expedition, the contrast between Lewis's celebrity and his inability to publish his journals or manage his governorship deepens his decline, while Sacagawea's unpaid departure and York's continued enslavement expose the moral contradictions at the heart of the mission. The eventual publication of the journals, years after Lewis's death, finally restores his place in American history.

The secondary moments that shaped the expedition's journey and its complicated aftermath.

Jefferson's first proposed expedition leader is revealed to be a French spy, prompting Jefferson to seek an American military man instead.

Hamilton's unexpected endorsement of Jefferson for president leads Jefferson to recruit Lewis as his personal secretary.

Lewis decides on his own to share equal command of the expedition with William Clark, reflecting unusual self-awareness.

An Oto chief returns to Lewis's camp naked to emphasize his tribe's poverty and displeasure with the meager diplomatic gifts.

Sergeant Floyd dies of a likely ruptured appendix, becoming the first US soldier to die west of the Mississippi River.

Sacagawea gives birth to her son Jean-Baptiste at Fort Mandan under Lewis's medical supervision.

Lewis and Clark send a detailed report to Jefferson from Fort Mandan, omitting any mention of the Mandan food assistance that kept them alive.

Lewis leads a ground party on foot and becomes the first to hear and then sight the Great Falls, confirming the correct river route.

Lewis's specially designed iron-frame boat fails to hold water due to a lack of waterproof pitch and must be abandoned and buried.

Lewis corners an elderly Shoshone woman and child in a ravine and wins their trust with gifts and sign language to make first contact.

Lewis writes his final expedition journal entry, noting it is too difficult to write while recovering from his accidental gunshot wound.

York demands his freedom from Clark as a reward for his expedition service; Clark refuses and later beats him for his reaction.

Lewis fails to make any progress on his expedition manuscript and stops communicating with Jefferson about it entirely.

Lewis attempts suicide twice while traveling by boat on his final journey before being placed on suicide watch at Fort Pickering.

Clark receives news of Lewis's death and resolves to find a writer to help him publish the unfinished expedition journals.

The Lewis and Clark Expedition was shaped at every stage by pivotal choices and unexpected revelations, beginning with Jefferson's decision to entrust the mission to an American military man after his first expedition choice was exposed as a foreign spy. Lewis's unilateral decision to share command equally with Clark proved one of his wisest judgments, while his omission of the Mandan tribe's life-saving food assistance from his official reports to Jefferson revealed the imperial mythology already being built around the expedition. The discovery of the Great Falls confirmed their route, but the catastrophic failure of Lewis's prized iron-frame boat stripped away his confidence at a critical moment, and his first dangerous contact with the Shoshone nearly ended the mission before it could cross the Rockies. On the return journey, Lewis wrote his final journal entry after being accidentally shot, and his post-expedition life unraveled through a cascade of failures: the unfinished manuscript, the denial of York's freedom, and mounting debts. His two suicide attempts on the boat before reaching Fort Pickering made his final fate all but inevitable, leaving Clark to salvage both the journals and Lewis's legacy from the wreckage.

The key decisions, discoveries, and emotional shifts that determined the expedition's fate.