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8.4-8.5.3 Thomas Jefferson to Meriwether Lewis, June 20, 1803, Instructions

President Jefferson’s instructions for Lewis, as co-leader of the Lewis & Clark expedition / Corps of Discovery, 1803-06.
Jefferson, Thomas
Library of Congress

Thomas Jefferson to Meriwether Lewis, Instructions. -06-20, 1803. Manuscript/Mixed Material.

Third president Thomas Jefferson (also author of the Declaration of Independence) believed that Native Americans were not at the same level of “civilization” and culture as white Americans. Jefferson was fascinated by Native American cultures and, broadly speaking, respected them. But he also believed that in order to survive, they must assimilate into white society as independent farmers, or move westward beyond the Mississippi River — which was the western border of the United States for the first two decades after independence. In 1803, Jefferson authorized the purchase of the vast Louisiana Territory — stretching from the Mississippi River west to the Rocky Mountains — from France for $15 million. This doubled the size of the nation. Jefferson then designed the Lewis & Clark Expedition (1804 – 1806), an ambitious effort to explore and map the Louisiana Territory and to secure the US claim to it. Jefferson gave the expedition broad goals, including scientific observation of plants and animals, climate, and geography. Another key aim was to establish friendly relations and trade (such as the fur trade) with the diverse Native American peoples who inhabited the Great Plains and Rockies. The expedition was led by two experienced US Army officers, Meriwether Lewis (also Jefferson’s trusted personal secretary) and William Clark. 


What were Jefferson’s aim(s) regarding Native Americans in the Louisiana Territory, as detailed in this letter to Captain Lewis? 

Do you think Jefferson’s goals concerning Native Americans were well intentioned? Why or why not? 

What details in these instructions for Captain Lewis stand out to you, and why? 



In 1803, Jefferson organized the Lewis & Clark Expedition — also commonly known as the Corps of Discovery — run by the US Army to explore and map the Louisiana Territory and to establish the US claim to this expansive region. In addition to the expedition’s scientific goals, Jefferson directed Lewis and Clark to look for an easy portage across the Rocky Mountains, from the headwaters of the Missouri River to the Columbia River system in the west. Such a water route across the continent would allow trade across the Pacific with Asia, but it proved not to exist. Key to this document, the Corps of Discovery was tasked with establishing good relations with the diverse Native American peoples of the Louisiana Purchase. Lewis and Clark struck a delicate balance in their approach to Native Americans: projecting US sovereignty over the territory and portraying Jefferson as the Indians’ new “Great White Father” in faraway Washington, DC, while also seeking peaceful trade and diplomatic ties. Overall, the expedition represented a striking mix of Enlightenment rationalism (wide-ranging inquiry about the world), and American empire-building and westward expansion.


The expedition set out from St. Louis in the spring of 1804, laboriously making their way up the Missouri River. They spent the winter of 1804 – 1805 at Fort Mandan, North Dakota, among the Mandan and Hidatsa peoples, crossed the Rocky Mountains with great difficulty, and descended the Snake and Columbia rivers to reach the Pacific coast in present-day Oregon late in 1805. They returned in 1806, bringing back to Jefferson an enormous amount of information. The explorers encountered some 50 Native American tribes, learning about their languages, customs, subsistence, and relations with neighboring peoples. Lewis and Clark’s interactions with Native Americans were almost entirely peaceful, yet the Corps of Discovery also unmistakably represented the vanguard of US sovereignty over the West. Here, students can discern Jefferson’s scientific, geographic, and ethnographic curiosity in the specific goals he laid out for Lewis. They can also judge what his attitude toward Native Americans was — paternalistic and superior, curious and open-minded, or some mix of the two?


[June 20 1803]
To Captain Meriwether Lewis esq. Capt. of the 1st. regimt, of Infantry of the US. of A.
…The object of your mission is to explore the Missouri river, & such principal stream of it as by it’s course and communication with the waters of the Pacific ocean whether the Columbia, Oregon, Colorado or any other river may offer the most direct & practicable water communication across this continent for the purposes of commerce.
Beginning at the mouth of the Missouri, you will take careful observations of latitude & longitude at all remarkable points on the river, & especially at the mouth of rivers, at rapids, at islands, & other places & objects distinguished by such durable natural marks… as that they may with certainty be recognized hereafter.
…The commerce which may be carried on with the people inhabiting the line your will pursue, renders a knolege of those people important. You will therefore endeavour to make yourself acquainted as far as a diligent pursuit of your journey shall admit, with the names of the nations & their numbers;
the extent & limits of their possessions; their relations with other tribes of nations;
their language, traditions, monuments;
their ordinary occupations in agriculture, fishing, hunting, war, arts & the implements for these;
their food, clothing, & domestic accomodations;
the diseases prevalent among them, & the remedies they use;
moral & physical circumstances which distinguish them from the tribes we know;
peculiarities in their laws, customs & dispositions;
and articles of commerce they may need or furnish & to what extent.
And considering the interest which every nation has in extending & strengthening the authority of reason & justice among the people around them, it will be useful to acquire what knolege you can of the state of morality, religion, & information among them; as it may better enable those who may endeavor to civilize & instruct them…