William Clark negotiated one-tenth of all ratified treaties between Native Americans and the US.

Clark’s maps provided the first detailed record of the American West

Covering over 8,000 miles, William Clark’s maps charted rivers, mountains, and tribal territories with remarkable accuracy. Equipped with sextants, compasses, telescopes, and more, Clark became an expert at surveying—requiring extensive celestial and topographical observations each day.

Lewis and Clark encountered more than 70 Native tribes during their journey

The Corps of Discovery’s diplomacy ranged from peaceful trade and vital aid from tribes like the Shoshone and Nez Perce to tense standoffs, most notably with the Teton Sioux, who nearly brought the expedition to a halt.

Jefferson sent Lewis and Clark to map, trade, and secure the West

Beyond seeking a water route to the Pacific, Jefferson tasked the Corps of Discovery with mapping the new Louisiana Territory, cataloging its resources, and establishing trade with Native nations.

The expedition included Clark’s enslaved servant, York

York, Clark’s enslaved servant, played a full role in the expedition—hunting, scouting, and aiding diplomacy with Native nations who were fascinated by his appearance. Despite his contributions, York remained enslaved for some time after the journey, though its uncertain if he remained so for the rest of his life. Explore every member of the Corps of Discovery here.

Explore Lewis and Clark's 8,000-mile journey in Google Earth.

Native voices share their histories along the Lewis and Clark National Historic Trail

Tribal historians recount their peoples' histories and perspectives on the Lewis and Clark expedition, offering an Indigenous narrative of the lands, encounters, and legacies that shaped the journey.

The Lewis and Clark Expedition brought along an estimated 120 gallons of whiskey and still ran out of alcohol halfway through the journey.

Lewis and Clark identified 122 animal species new to science.

Jefferson’s Lewis and Clark expedition joined the centuries-long hunt for Northwest Passage

For centuries, leaders pursued a direct seafaring trade route from Europe to Asia. Jefferson joined this quest by sending Lewis and Clark west, though they confirmed no such practical interior route existed across the continent.

Jefferson omitted a plan to go beyond the Louisiana Territory in his funding request

In January of 1803, the president sought $2,500 to fund the expedition (though it likely cost closer to $50,000). The ostensible rationale for the journey was to explore the newly purchased territory, but Jefferson did not mention he wanted Lewis and Clark to go beyond the newly acquired territory for several reasons.

Lewis and Clark’s journey became a blueprint for future exploration

Combining science, diplomacy, and logistics, the Corps of Discovery created a model for later expeditions—from charting the Arctic to NASA’s space missions.

The Lewis and Clark Expedition unexpectedly ran into Sacagawea's long-lost family in the Rocky Mountains.

The 1783 peace treaty with Britain formally ended the Revolutionary War and nearly doubled the size of the United States.

The Lewis and Clark expedition lasted over two years

The Corps of Discovery departed St. Louis in May 1804 and returned in September 1806, covering more than 8,000 miles by boat, horseback, and on foot. See a timeline of the journey’s key events.

The Corps of Discovery braved wildlife, weather, and near-starvation

Along their 8,000-mile trek through territory populated by tribes suspicious of their intentions, Lewis and Clark’s party faced many dangers—including grizzly bear attacks, freezing winters, treacherous river crossings, and periods of near-starvation. Watch a 30-minute elaboration of their heroic efforts here.

Discover the 'American Serengeti' Lewis and Clark first recorded

This podcast traces the 19th-century exploration of the Great Plains' biodiversity—beginning with Lewis and Clark's wildlife cataloging and continuing through a century of documenting the Natural West's remarkable species and landscapes.

The expedition produced the first detailed climate records of the West

Lewis and Clark logged daily temperature, weather, and seasonal patterns throughout their journey, creating the earliest systematic meteorological record for the western territories of the United States. Their observations helped overturn longstanding views that weather west of the Appalachians was similar to the East Coast.

The Lewis and Clark expedition purchased more than 260 separate items to supply their journey.

The expedition documented 240 plant species, 178 new to western science

Lewis and Clark’s botanical records introduced species to Americans like bitterroot, ponderosa pine, and Oregon grape—plants unknown to western science at the time. See a selection of these species in this image gallery.

The Corps traded gifts with many native tribes as a sign of goodwill

They offered peace medals, beads, cloth, and mirrors, while receiving food, horses, furs, and guidance that helped them navigate and survive the western wilderness. This image collection showcases items the expedition collected.

One Native leader tried to save his people's land by building a nation

As the US pushed westward in the 19th century, one leader of the Ojibwe people fought back not with arms but with politics, seeking to preserve his people's territory and way of life by building a formal Native nation capable of negotiating on equal footing with the US government.

As president, Thomas Jefferson expanded federal power despite opposing centralized authority

Although Jefferson argued for limited national power, his presidency expanded federal authority through actions such as the Louisiana Purchase, territorial governance, and federal enforcement—reflecting a pragmatic departure from his earlier strict interpretation of the Constitution.

The Indian Removal Act of 1830 forcibly displaced tens of thousands of Native Americans

Signed by President Andrew Jackson, the act authorized the federal government to negotiate treaties relocating Native nations from their Southeastern homelands to lands west of the Mississippi, often by force.

A tense standoff with the Teton Sioux nearly ended the expedition

In 1804, the Teton Sioux seized a Corps of Discovery boat during a Missouri River meeting, sparking a dangerous standoff. The conflict eased only after careful diplomacy.

The Dawes Act of 1887 broke up communally held tribal lands

Sometimes called the General Allotment Act, the Dawes Act divided reservation land into individual plots assigned to Native Americans, while "surplus" land was sold to white settlers. The policy led to Native tribes losing roughly 90 million acres, about two-thirds of their remaining land.

Meriwether Lewis grew up in the same neighborhood as Jefferson

Hailing from Jefferson’s Albemarle County neighborhood in Virginia, Lewis was a trusted aide and former Army officer. After leading the Corps of Discovery, he became Louisiana Territory governor in 1806, dying three years later under mysterious circumstances.

Sacagawea’s skills and presence were vital to the expedition’s success

The group hired French-Canadian trader Toussaint Charbonneau and his wife Sacagawea to serve as translators. Sacagawea became invaluable to the Corps, as she could speak Shoshone and had a familiarity with the geography of the region. Acting as interpreter and cultural bridge, Sacagawea helped secure Shoshone horses, identified key landmarks, and signaled peaceful intent to other tribes.

Madison urged Jefferson to accept the Louisiana Purchase despite constitutional concerns

As secretary of state, James Madison helped negotiate the 1803 Louisiana Purchase and persuaded Thomas Jefferson to proceed, arguing that the strategic and economic stakes outweighed the unresolved constitutional questions.

Some tribes push for national parks to be under Indigenous control

Ojibwe author and academic David Treuer talks about his push for 80 million acres of American national park land to be returned to Indigenous stewards. Treuer proposes the government grant control of this land to a consortium of tribes, which would maintain and manage it for use by all Americans.

Cases during John Marshall's tenure defined the principles of federal Indian law

During Marshall's tenure, three landmark rulings—Johnson v. M'Intosh, Cherokee Nation v. Georgia, and Worcester v. Georgia—established foundational doctrines of federal Indian law, defining tribal sovereignty, limiting state authority, and placing primary responsibility for Native affairs in the federal government.

The reservation system gives tribes limited self-governance while keeping them under federal control.

Thomas Jefferson and John Marshall clashed over national power and states' rights

Distant cousins Jefferson and Marshall advanced opposing constitutional visions—Jefferson favoring states' rights and local majorities, while Marshall defended broad federal authority and judicial review. Through decisions such as McCulloch v. Maryland, Marshall advanced national supremacy over state resistance.

Jefferson feared European control in the West of North America

Jefferson pushed for the Louisiana Purchase to prevent France or Spain from dominating the western frontier, securing control of the Mississippi River and vast lands that he felt were essential to America’s strategic and economic future.

Sacagawea's son, Jean Baptiste, who was born during the Lewis and Clark expedition, traveled to Europe as a duke's companion before returning to the American West.

George Washington was an expert in maps and cartography

Trained as a surveyor, Washington routinely studied, annotated, and drew maps throughout his life. He relied on cartography to navigate frontier lands, plan military campaigns across vast distances, and make strategic decisions on borders, settlement, and governance.

The creation of the parks often involved displacing Native tribes

Early parks like Yellowstone, Glacier, and Yosemite involved the removal of tribal communities like the Shoshone, Crow, and Nez Percé, undermining the popular narrative that parks preserved an uninhabited wilderness.

Marshall was briefly secretary of state and chief justice at the same time

Appointed secretary of state by John Adams in 1800, Marshall oversaw foreign policy during disputes with France, Britain, and Spain, including support for the Convention of 1800. For about a month in early 1801, he served as both secretary of state and chief justice.

The Trail of Tears killed thousands of Native Americans forced from their homelands

After the Indian Removal Act passed, the US Army marched the Cherokee and other nations hundreds of miles to the designated "Indian Territory" in present-day Oklahoma. Thousands died from starvation and disease along the way.

American archaeology has a complicated legacy

Many national parks were discovered through American archaeological expeditions and, consequently, included the looting of Native American cultural sites and artifacts.

Native Americans were not granted US citizenship until 1924

The Indian Citizenship Act granted citizenship to all Native Americans born in the US, more than 130 years after the Constitution's ratification. Even then, some states continued to deny Native Americans the right to vote for decades.

In the 1950s, the federal government tried to dissolve tribal nations and end their sovereignty

A federal policy called "termination" withdrew official recognition from more than 100 tribes in the 1950s, cutting off federal services and subjecting reservation land to state taxes and sale.

Foreign policy and war defined Madison's presidency

During James Madison's presidency, disputes with Britain and France over trade, maritime rights, and impressment dominated foreign policy, culminating in the War of 1812 and shaping how the United States engaged with major European powers.

The Iroquois Confederacy's political structure may have shaped the US Constitution

Centuries before the US existed, six Indigenous nations—the Mohawk, Oneida, Onondaga, Cayuga, Seneca, and Tuscarora—united under a shared constitution known as the Great Law of Peace. Some historians argue that the framework of federalism and representative councils influenced the American founders.

European diseases killed a massive share of the Native American population

After Western contact, epidemic diseases devastated Indigenous communities. By 1920, the Native American population of the US had fallen to roughly 270,000, compared with an estimated 1.2 to 18 million at the time of European arrival.

Hear the story of the early American environmentalists who shaped the public lands we enjoy today.

The first test of America's war powers came just a decade after the Constitution was ratified

During the undeclared Quasi-War with France in 1800, the Supreme Court ruled in Bas v. Tingy that Congress had authorized a valid "imperfect war" through statutes alone, without a formal declaration, establishing that there is a legal spectrum between peace and declared war.

How the US took half of Mexico

In just two years, the United States redrew the map of North America. Sparked by border disputes in Texas and fueled by President James Polk’s drive for expansion, the Mexican–American War (1846–1848) reshaped both nations.

Yellowstone was the world's first national park

Before it was designated as such, it was home to 27 Indigenous tribes, including the Blackfeet, Crow, and Nez Perce. European trappers and traders traveling west were entranced by the area’s stunning beauty and natural resources, fueling a push for the government to preserve the land for future generations.

John Marshall gained national prominence during the XYZ Affair

In 1797, President John Adams sent Marshall to France amid seizures of American ships. French intermediaries demanded loans and bribes before talks, and Marshall refused. Publication of the dispatches fueled the Quasi-War and elevated his reputation in the United States.

Later in life, Washington privately grew critical of slavery—while continuing to uphold it publicly

His private letters increasingly described slavery as unjust and incompatible with Republican ideals, and his final will ordered the eventual emancipation of those he legally owned. At the same time, he enforced slave labor, signed pro-slavery laws, and took no public action to dismantle the system.