According to the archivists at the Library of Congress, Jefferson made the request in a secret message in order to hide his intentions from his political enemies in the Federalist Party.
Congress agreed to fund the expedition that would be led by Meriwether Lewis and William Clark. The 8,000-mile expedition provided the US Government with its first glimpse of the vast lands that lay west of the Mississippi River.
Transcript of Jefferson’s Secret Message to Congress Regarding the Lewis & Clark Expedition (1803)
Gentlemen of the Senate, and of the House of Representatives:
As the continuance of the act for establishing trading houses with the Indian tribes will be under the consideration of the Legislature at its present session, I think it my duty to communicate the views which have guided me in the execution of that act, in order that you may decide on the policy of continuing it, in the present or any other form, or discontinue it altogether, if that shall, on the whole, seem most for the public good.
The Indian tribes residing within the limits of the United States, have, for a considerable time, been growing more and more uneasy at the constant diminution of the territory they occupy, although effected by their own voluntary sales: and the policy has long been gaining strength with them, of refusing absolutely all further sale, on any conditions; insomuch that, at this time, it hazards their friendship, and excites dangerous jealousies and perturbations in their minds to make any overture for the purchase of the smallest portions of their land. A very few tribes only are not yet obstinately in these dispositions.
In order peaceably to counteract this policy of theirs, and to provide an extension of territory which the rapid increase of our numbers will call for, two measures are deemed expedient.
First: to encourage them to abandon hunting, to apply to the raising stock, to agriculture and domestic manufacture, and thereby prove to themselves that less land and labor will maintain them in this, better than in their former mode of living. The extensive forests necessary in the hunting life, will then become useless, and they will see advantage in exchanging them for the means of improving their farms, and of increasing their domestic comforts.
Secondly: to multiply trading houses among them, and place within their reach those things which will contribute more to their domestic comfort, than the possession of extensive, but uncultivated wilds. Experience and reflection will develop to them the wisdom of exchanging what they can spare and we want, for what we can spare and they want. In leading them to agriculture, to manufactures, and civilization; in bringing together their and our settlements, and in preparing them ultimately to participate in the benefits of our governments, I trust and believe we are acting for their greatest good.
At these trading houses we have pursued the principles of the act of Congress, which directs that the commerce shall be carried on liberally, and requires only that the capital stock shall not be diminished. We consequently undersell private traders, foreign and domestic, drive them from the competition; and thus, with the good will of the Indians, rid ourselves of a description of men who are constantly endeavoring to excite in the Indian mind suspicions, fears, and irritations towards us.
A letter now enclosed, shows the effect of our competition on the operations of the traders, while the Indians, perceiving the advantage of purchasing from us, are soliciting generally, our establishment of trading houses among them. In one quarter this is particularly interesting. The Legislature, reflecting on the late occurrences on the Mississippi, must be sensible how desirable it is to possess a respectable breadth of country on that river, from our Southern limit to the Illinois at least; so that we may present as firm a front on that as on our Eastern border.
We possess what is below the Yazoo, and can probably acquire a certain breadth from the Illinois and Wabash to the Ohio; but between the Ohio and Yazoo, the country all belongs to the Chickasaws, the most friendly tribe within our limits, but the most decided against the alienation of lands. The portion of their country most important for us is exactly that which they do not inhabit.
Their settlements are not on the Mississippi, but in the interior country. They have lately shown a desire to become agricultural; and this leads to the desire of buying implements and comforts. In the strengthening and gratifying of these wants, I see the only prospect of planting on the Mississippi itself, the means of its own safety. Duty has required me to submit these views to the judgment of the Legislature; but as their disclosure might embarrass and defeat their effect, they are committed to the special confidence of the two Houses.
While the extension of the public commerce among the Indian tribes, may deprive of that source of profit such of our citizens as are engaged in it, it might be worthy the attention of Congress, in their care of individual as well as of the general interest, to point, in another direction, the enterprise of these citizens, as profitably for themselves, and more usefully for the public.
The river Missouri, and the Indians inhabiting it, are not as well known as is rendered desirable by their connexion with the Mississippi, and consequently with us. It is, however, understood, that the country on that river is inhabited by numerous tribes, who furnish great supplies of furs and peltry to the trade of another nation, carried on in a high latitude, through an infinite number of portages and lakes, shut up by ice through a long season.
The commerce on that line could bear no competition with that of the Missouri, traversing a moderate climate, offering according to the best accounts, a continued navigation from its source, and possibly with a single portage, from the Western Ocean, and finding to the Atlantic a choice of channels through the Illinois or Wabash, the lakes and Hudson, through the Ohio and Susquehanna, or Potomac or James rivers, and through the Tennessee and Savannah, rivers.
An intelligent officer, with ten or twelve chosen men, fit for the enterprise, and willing to undertake it, taken from our posts, where they may be spared without inconvenience, might explore the whole line, even to the Western Ocean, have conferences with the natives on the subject of commercial intercourse, get admission among them for our traders, as others are admitted, agree on convenient deposits for an interchange of articles, and return with the information acquired, in the course of two summers.
Their arms and accouterments, some instruments of observation, and light and cheap presents for the Indians, would be all the apparatus they could carry, and with an expectation of a soldier’s portion of land on their return, would constitute the whole expense. Their pay would be going on, whether here or there.
While other civilized nations have encountered great expense to enlarge the boundaries of knowledge by undertaking voyages of discovery, and for other literary purposes, in various parts and directions, our nation seems to owe to the same object, as well as to its own interests, to explore this, the only line of easy communication across the continent, and so directly traversing our own part of it. The interests of commerce place the principal object within the constitutional powers and care of Congress, and that it should incidentally advance the geographical knowledge of our own continent, cannot be but an additional gratification.
The nation claiming the territory, regarding this as a literary pursuit, which is in the habit of permitting within its dominions, would not be disposed to view it with jealousy, even if the expiring state of its interests there did not render it a matter of indifference.
The appropriation of two thousand five hundred dollars, “for the purpose of extending the external commerce of the United States,” while understood and considered by the Executive as giving the legislative sanction, would cover the undertaking from notice, and prevent the obstructions which interested individuals might otherwise previously prepare in its way.
Jan. 18. 1803
Transcription via the Library of Congress – Paragraph breaks added for readability