Journals of the Lewis and Clark Expedition

From 1804 to 1806, Meriwether Lewis and William Clark led the Corps of Discovery, exploring the territory of the Louisiana Territory, which the United States had recently acquired. The two men’s journals of their expedition (with contributions from others in the Corps) provide an account of the efforts of Lewis and Clark to achieve the varied goals of the Corps of Discovery.

President Thomas Jefferson (responsible for the Louisiana Purchase as well as the commissioning of the Lewis and Clark expedition) wanted the Corps of Discovery to proclaim American sovereignty over the Native American tribes in the Louisiana Territory and to study and record details of the geography and natural resources of the area. The expedition did so and also cataloged hundreds of examples of the flora and fauna of the region. The journals provide rich information on the geography and climatology of the West, from the expedition’s initial route along the Missouri River to their ultimate arrival at the Pacific Ocean. A particularly striking example is the passage concerning the strong winds and resulting sandstorm that affected the Corps in April of 1805—a phenomenon that would have been rare in the eastern United States.

Their journals also detail the interactions between the Lewis and Clark and the leaders of the numerous Native American tribes they encountered on their journey—in particular, they describe the complexity of the relations between the different tribes and posit a role for the United States as a potential ally. The discussions between Lewis and Clark and the various native leaders moved beyond the realm of diplomacy, touching on commercial matters as well as arranging for tribal members to accompany the Corps of Discovery.