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 connection 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 can not but be an additional gratification.  The nation claiming the territory, regarding this as a literary pursuit, which it 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 $2,500 “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.