The Lewis and Clark
Expedition

Nicholas King (1771-1812) with
annotations by Meriwether Lewis
(1774-1809)
[Map of Western North America]
Manuscript map on paper, 1803
Geography & Map Division

Thomas Jefferson to
Meriwether Lewis (1774-1809)
Press copy in the hand of
Jefferson, June 20, 1803
Page 2
Manuscript Division

Samuel Lewis
A Map of Lewis and Clark's Track
Across the Western Portion of
North America from Mississippi
to the Pacific Ocean.
Philadelphia:1814
Printed map
Geography & Map Division

In June 1803, President Thomas Jefferson wrote to Meriwether Lewis (1774-1809), his private secretary and a U.S. army captain, instructing the expedition to explore the Missouri basin by crossing over the Rocky Mountains to the Pacific Ocean. Among the Library's significant collection of manuscripts and published maps documenting the expedition of Meriwether Lewis and William Clark (1770-1838) to the Pacific Northwest between 1800 and 1803 are published maps issued with the final reports of the expedition, interim composite maps showing the progress of the expedition, and maps used or consulted in planning the expedition.

The example shown here is a composite map drawn in 1803 by Nicholas King, a War Department copyist, from published and manuscript sources, at the request of Thomas Jefferson and Secretary of the Treasury Albert Gallatin. The map reflects the geographical concepts of government leaders on the eve of the expedition. It is believed that Lewis and Clark carried this map on the expedition, at least as far as the Mandan-Hidasta villages on the Missouri River, where Lewis annotated in brown ink additional information obtained from fur traders. This map, as well as twelve other manuscript maps, which are thought to have belonged to William Clark, was transferred to the Library of Congress in 1925 from the Office of Indian Affairs.

Among the Library's original maps documenting the expedition (1803-06) of Lewis and William Clark are published maps issued with the final reports of the expedition, as well as planning maps and those actually carried with them. This 1814 map was the first composite map to report the expedition's discoveries.

One of the reasons the Lewis and Clark expedition succeeded in traversing the northwestern portion of North America and reaching the Pacific Ocean was because the leaders meticulously consulted the best cartographic sources that were available at the beginning of the nineteenth century to create a composite image of the geography of the western portion of North America.