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Jefferson's Letter of Instruction to Meriwether Lewis

On June 20, 1803 President Thomas Jefferson gave instructions in a letter to Captain Meriwether Lewis on what he expected Lewis and Clark to learn on their journey west. Exploring the newly acquired Louisiana Purchase in a systematic and scientific manner was important to President Jefferson. He outlined his interests for the collection of data, study of the land, its peoples and its natural world, by Captains Lewis and Clark.



"To Meriwether Lewis, esquire, Captain of the 1st regiment of infantry of the United States of America.

"Your situation as Secretary of the President of the United States has made you acquainted with the objects of my confidential message of Jan. 18, 1803, to the legislature. You have seen the act they passed, which, tho' expressed in general terms, was meant to sanction those objects, and you are appointed to carry them into execution.

"Instruments for ascertaining by celestial observations the geography of the country thro' which you will pass, have been already provided. Light articles for barter, & presents among the Indians, arms for your attendants, say for from 10 to 12 men, boats, tents, & other travelling apparatus, with ammunition, medicine, surgical instruments & provision you will have prepared with such aids as the Secretary at War can yield in his department; & from him also you will recieve authority to engage among our troops, by voluntary agreement, the number of attendants above mentioned, over whom you, as their commanding officer are invested with all the powers the laws give in such a case.

[ . . . ]

"The object of your mission is to explore the Missouri river, & such principal stream of it, as, by it's course & communication with the water of the Pacific ocean may offer the most direct & practicable water communication across this continent, for the purposes of commerce.

[ . . . ]

"Your observations are to be taken with great pains & accuracy to be entered distinctly, & intelligibly for others as well as yourself, to comprehend all the elements necessary, with the aid of the usual tables to fix the latitude & longitude of the places at which they were taken, & are to be rendered to the war office, for the purpose of having the calculations made concurrently by proper persons within the U.S. Several copies of these as well as of your other notes, should be made at leisure times, & put into the care of the most trustworthy of your attendants, to guard by multiplying them against the accidental losses to which they will be exposed. A further guard would be that one of these copies be written on the paper of the birch, as less liable to injury from damp than common paper.

"The commerce which may be carried on with the people inhabiting the line you will pursue, renders a knolege of these people important. You will therefore endeavor 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 or nations;
their language, traditions, monuments;
their ordinary occupations in agriculture, fishing, hunting, war, arts, & the implements for these;
their food, clothing, & domestic accommodations;
the diseases prevalent among them, & the remedies they use;
moral and physical circumstance which distinguish them from the tribes they 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 endeavor to civilize & instruct them, to adapt their measures to the existing notions & practises of those on whom they are to operate.

"Other objects worthy of notice will be
the soil & face of the country, it's growth & vegetable productions, especially those not of the U.S.
the animals of the country generally, & especially those not known in the U.S. the remains & accounts of any which may be deemed rare or extinct;
the mineral productions of every kind; but more particularly metals, limestone, pit coal & saltpetre;
salines & mineral waters, noting the temperature of the last & such circumstances as may indicate their character;
volcanic appearances;
climate as characterized by the thermometer, by the proportion of rainy, cloudy & clear days, by lightening, hail, snow, ice, by the access & recess of frost, by the winds, prevailing at different seasons, the dates at which particular plants put forth or lose their flowers, or leaf, times of appearance of particular birds, reptiles or insects.
[ . . . ]

"Given under my hand at the city of Washington, this 20th day of June 1803."

Th: Jefferson Pr. US. of America


The entire text of the letter can be found on the Thomas Jefferson Foundation's web site at http://www.monticello.org/jefferson/lewisandclark/instructions.html.