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

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.

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

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

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.

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.

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.

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 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.

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.

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.

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.

A free archive of firsthand historical documents from explorers of America

Maintained by the Wisconsin Historical Society, the American Journeys collection contains more than 18,000 pages of primary source documents—journals, letters, maps, and accounts written between roughly 1000 CE and the early 1800s. These include eyewitness records of the Norse arrival in North America, Spanish conquistador expeditions, and the Lewis and Clark journey. Browse this list of highlights where pages from the original texts are specified (clicking a link opens a PDF).

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

37 maps that explain the American Civil War

This collection of 37 maps tells the story of the American Civil War as well as any historical account. See how and where the war began and why, and where the major battles were fought. Discover how the North achieved victory and the many ways the war changed America forever.

How one biologist drew a national park's definitive map

Long before GPS, biologist John Cely mapped the swampy terrain of South Carolina's Congaree National Park by hand, and mostly from memory. The map was so accurate, it became the preferred resource for the park's rangers. This Atlas Obscura article explores how Cely acquainted himself with the park's particulars and how the map grew from an unofficial peculiarity into the park's definitive guide.

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 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.

View depictions of world maps throughout history

The first map to use latitude and longitude positions was created by Ptolemy in 150 CE, over 700 years after the oldest known world map, the Imago Mundi, was made with a Babylonian clay tablet. The Spanish crown created a secret master map from hundreds of sailors’ reports.

The first women to run the Colorado River discovered four plant species

Over 45 days and 660 miles, Elzada Clover and Lois Jotter identified more than 50 species in what was the first botanical survey of the region. Expected to help navigate boats and cook for the crew during the day, their work was confined to before dawn and after dusk.

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 purchased more than 260 separate items to supply their journey.

Search this digital archive of 19th-century "panoramic" maps of US and Canadian cities

The panoramic map was a popular cartographic form used to depict U.S. and Canadian cities and towns during the late nineteenth and early twentieth centuries. You can peruse a gallery of almost 2,000 of them in this digital archive from the Library...

Explore a detailed map of Odysseus' fictional journey from 'The Odyssey.'

American oceanographic cartographer Marie Tharp's discovery of the Mid-Atlantic Ridge, which supported the idea that continents move over time, was initially dismissed as 'girl talk.'

Sculptor and painter Charles M. Russell focused on the Old West

The Montana artist, known for his realistic portrayals of cowboys and Native American life, began to gain national attention after traveling to New York and establishing connections in the art world. Still, he spent most of his time in Great Falls, Montana, where he completed approximately 4,000 works.

The history of the world map

What did people used to think the world looked like? From the beginning of human history to right before the age of exploration, learn how the world maps were created.

'Grand Canyon of the Yellowstone,' a work by American painter Thomas Moran, inspired Congress to establish Yellowstone National Park.

Explore a collection of famous literary maps, including original images from 'Treasure Island,' 'The Swiss Family Robinson, ' and 'Walden.'

Visualize every day of the American Civil War, in which fighting took place in a majority of the country.

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

No map of the Earth is perfect because each introduces inaccuracies in the shape, size, or orientation of landmasses and oceans by trying to flatten the planet's curved surface.

Mapping early New York

Want to see how Wall Street (and New York City as a whole) has changed over time? Use this timeline and map to see Manhattan today overlaid with the precise boundaries of early land grants to the Dutch in the 1600s. Scroll through the progress of city building through the first century of European settlement there.

Create digital maps of Earth with custom sketches and labels

In this interactive, users can apply layers to various base maps to display natural and human features, including geological activity, biomes, ocean currents, population densities, and light pollution. Custom legends, markers, and drawings can be used to highlight prominent features.

Charting 4,000 years of human history

Care to hang all of human history on your wall? This data visualization charts 4,000 years of humanity. This "histomap" was originally published in 1931 and sold for $1 per copy of the 5-foot-long chart. It was said to detail the course of...

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.

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.

A collection of contemporary maps from World War II

Newspapers published detailed maps of the conflict in real-time. See different portrayals of the situation, ranging from propaganda maps to speculative maps about the war's outcome. The fascinating depictions reveal how maps can show us the aspirations and intentions of different players in a global conflict.

Explore landforms that exist across America's national parks

Landforms are not just scenic vistas; they are geological storytellers that shape ecosystems, climates, and our understanding of Earth's history. In this comprehensive look at landforms from the National Park Service, you will learn not only about different types of American landforms, but you will understand how these geological features are shaped by various forces, how they reveal an area's geological history, and how they influence climate and ecology.

Travel the 363-mile Erie Canal, the waterway that cut freight costs by 90% and opened the American frontier.

Explore rare artifacts from the archives at Mount Vernon

This series from Washington's Presidential Library showcases rare books, maps, letters, and artifacts from his collection. It illuminates how he learned, governed, traveled, and understood the world around him.

Cook’s ‘Travellers Handbooks’ were precursors to the travel guide

Long before Rick Steves or Lonely Planet, Thomas Cook’s “Travellers Handbooks” offered maps, recommendations, and tips for 19th-century tourists in unfamiliar locations.

The Civil War turned the Continental Divide into an American symbol of identity

Historians argue that the boundary only became a celebrated American symbol in the 1860s, when Civil War-era leaders promoted a west-east geographic divide to replace the devastating north-south political divide, and that the term's use spiked after the transcontinental railroad crossed it in 1868.

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.

Explore an interactive map of battles from the American Revolution, along with detailed summaries of each engagement.

See a timeline of colonial settlement in North America.

US westward expansion—and the status of slavery in the new territories—was a major cause of the American Civil War

The addition of new western lands forced the nation to confront whether slavery would spread beyond the South. Each debate over the admission of a new state sharpened the divide between free and slaveholding regions.

The Appalachian Mountains blocked east–west boat travel until the Erie Canal

The Appalachian Mountains, spanning from Alabama to Canada, long hindered inland commerce. The Erie Canal created the first reliable water route through the range by leveraging the natural valley of the Mohawk River, revolutionizing trade and migration.

Common mistakes we make about the world map

Maps have long loosely approximated what the world actually looks like. Here's a few common errors that persist due to outdated conceptions of the world.