The rapid and wonderful increase in the territories and inhabitants of the United States, has necessarily laid open the greater part of North America to our acquaintance.  The United States, limited in their wish and endeavours to extend themselves on the north by the British possessions there, and on the south by the Spanish territories, and moreover drawn towards the interior and the shores of the Pacific by the grand natural navigation which the Mississippi and its numerous streams afford for inland commerce, and by the commercial access to the wealth of the East which the possession of the shores of the Pacific would open to them, have pushed their territories towards the west.  First, the Alleghany Mountains, a feeble barrier to an encreasing population, and a most enterprising as well as unsettled people, were passed; then the Mississippi was reached and crossed; and at present the government of the United States are preparing the way for extending their territories gradually to the Western Ocean itself, and for spreading their population, as they go westwards, to the north and the south, as far as their limits, will admit.

All those countries, over which they have spread themselves, are of course now well known, principally from the accounts published by Europeans, and especially Englishmen, who have been tempted to explore them, or to settle there.  The government of the United States itself has not been backward in setting on foot exploratory travels into the immense districts to the west of the Mississippi:  to these enterprizes they seem to have been particularly directed and stimulated by the acquisition of Louisiana from France, a country “rich and varied in its soil, almost inexhaustible in natural resources, and almost indefinite in extent.”

This acquisition was made in the year 1803, and within four years of this period, three exploratory expeditions were sent out by the United States.  The principal object of the first, which was under the direction of Major Pike, was to trace the Mississippi to its source, and to ascertain the direction of the Arkansa and Red Rivers, further to the west.  In the course of this journey, an immense chain of mountains, called the Rocky Mountains, was approached, which appeared to be a continuation of the Andes.  The ulterior grand object, however, of this expedition was not obtained, in consequence of the Spaniards compelling Major Pike to desist and return.  A second attempt was made, by another party, but the Spaniards stopped them likewise.  In the years 1804, 5, and 6, Captains Lewis and Clarke explored the Missouri to its source, crossed the Rocky Mountains, and proceeding towards the North Pacific Ocean, ascertained, the origin and course of the River Columbia.