Map of Lewis and Clark's Track

This map, titled A Map of Lewis and Clark's Track across the Western Portion of North America from the Mississippi to the Pacific Ocean, published in 1814, is based on William Clark’s cartography from the 1804–1806 Expedition and information from fur trappers and other explorers in the American West after 1807. Geographer John Allen has called the map “an item of superlative craftsmanship and analysis.” In addition to new cartographic information, the map also marks the end of the search for a Northwest Passage, a fabled waterway that many Americans and Europeans hoped would provide an easy passage from the Atlantic to the Pacific. 

At the beginning of the nineteenth century, it was generally thought that the headwaters of the Missouri River were in close proximity to the headwaters of the Columbia River and that only a plateau or a gentle “pyramidal height-of-land” separated the two systems. Clark and Meriwether Lewis proved this theory wrong when they found that a series of rugged mountain ranges divided the continent. Moreover, the rivers descending the western slope of the Rocky Mountains proved to be unnavigable.

Clark’s map was copied for engraving and printing by Philadelphia cartographer Samuel Lewis. It was one of the most important maps created during the nineteenth century, and was the foundation upon which the next generation of American cartographers built their knowledge of western geography.

OHS has a copy, but it is best viewed on the Library of Congress digital site, here.

Written by Kathy Tucker and Cain Allen, 2002, 2004; revised 2021

Further Reading:
Allen, John Logan. Passage through the Garden: Lewis and Clark and the Image of the American Northwest. Urbana: University of Illinois Press, 1975.

Lewis, Meriwether, and William Clark. The Journals of the Lewis and Clark Expedition. Vol. 1, Atlas of the Lewis and Clark Expedition, edited by Gary E. Moulton. Lincoln: University of Nebraska Press, 1983.

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Captain Meriwether Lewis's Branding Iron

Captain Meriwether Lewis carried this branding iron on the Corps of Discovery’s 1804–1806 exploration of western North America (the captains also carried a smaller "stirrup iron" used to brand horses). The details of this artifact’s manufacture are unknown, but historians have speculated that it might have been produced in 1804 …

Estimate of Western Indians, Lewis and Clark Journals

Charged by Pres. Thomas Jefferson with recording the names of Native communities and estimating the size of their populations, Captains Meriwether Lewis and William Clark took note of the number of inhabitants in each Native settlement they passed on their journey to the Pacific Ocean. They compiled that information during …

Meriwether Lewis to Thomas Jefferson, 1805

Captain Meriwether Lewis wrote this letter to President Thomas Jefferson in early April 1805 from Fort Mandan, near present-day Washburn, North Dakota. It was hand-copied and the spelling corrected in about 1901 by one of Lewis’s relatives for Eva Emery Dye, a writer in Oregon City who was doing research …

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This entry was last updated on March 29, 2021