THE Lewis and Clark Expedition was one of the most dramatic and significant episodes in the history of the United States. In 1804-6 it carried the destiny as well as the flag of our young Nation westward from the Mississippi across thousands of miles of mostly unknown landup the Missouri, over the Rocky Mountains, and on to the Pacific. This epic feat not only sparked national pride, but it also fired the imagination of the American people and made them feel for the first time the full sweep of the continent on which they lived. Equally as important, the political and economic ramifications of the trek vitally affected the subsequent course and growth of the Nation.
In its scope and achievements, the expedition towers among the major explorations of the North American Continent and the world. Its members included the first U.S. citizens to cross the continent; the first individuals to traverse it within the area of the present United States; and the first white men to explore the Upper Missouri area and a large part of the Columbia Basin as well as to pass over the Continental Divide within the drainage area of the two rivers. 
Before Lewis and Clark, the trans-Mississippi West was largely a virgin land. British, Spanish, and French explorers and traders had barely penetrated it. Apart from a tiny fringe of French-American settlement in the St. Louis area and elsewhere along the Mississippi and small Spanish colonies in the Rio Grande Valley of New Mexico and in California, the region was virtually uninhabited by whites. For the most part enveloped in rumor, fantasy, and mystery, it was almost as strange as outer space would be to the later generation that was first to orbit the earth and put a man on the moon.
The men of the expedition made their way through this vast land, living mainly off its resources and superbly adapting themselves to the new conditions it imposed. They encountered alien tribes and menacing animals. On foot, on horseback, and by boat, they pushed over jagged mountain ranges, across seemingly endless plains, through tangled forests, against powerful currents and raging waters. Under two determined captains and three hardy sergeants, the explorers met danger as a matter of course and suffered hunger, fatigue, privation, and sickness.
Despite all these obstacles, the project was brilliantly managed and executed. Few, if any, comparable explorations have been so free of blunders, miscalculations, and tragedy. Its leaders were masters of every situation. Only one individual lost his life, but of a disease that could not have been cured in the best hospitals of the day. Clashes with the Indians were limited to two unavoidable instanceswith the Teton Sioux and a small party of Blackfeetbut in both cases Lewis and Clark triumphed and their firmness won the respect of the natives.
Considering the frequent stress and their close association over a long period of time, relations between the two captains were remarkably harmonious. This was also true of their party, which when fully assembled consisted of a mixture of white, black, and Indian from various sections of the country and Canada.
Not many explorers in the history of the world have provided such exhaustive and accurate information on the regions they probed. Assigning high priority to the quest for knowledge, Lewis and Clark laboriously recorded in their journals and notebooks observations about the characteristics, inhabitants, and resources of the country through which they passed. All told, they amassed far more reliable data on the West than had ever been acquired before.
The expedition was as astutely conceived as it was efficiently conducted. President Thomas Jefferson organized it in 1802 because he foresaw the continental destiny of the Nation. At that time, the United States had been independent from Britain for only 19 years and depended to a large extent for its very survival on the conflicts generated by imperial rivalry among Britain, Spain, and France. Furthermore, the Union consisted of only 16 States, the Original Thirteen plus Vermont, Kentucky, and Tennessee. Although some settlers had reached the Mississippi, most parts of the western portion of the national domain were not settled at all and most of the remainder was but sparsely populated. In 1803 Ohio came into the Union, and the United States purchased from France the Louisiana Territory, a huge and ill-defined block of territory west of the Mississippi.
The purchase represented the replacement of French interests by those of the United States in the eastern part of the trans-Mississippi West, all of which had long been a sort of international no-man's land by virtue of the undulating fortunes of global politics. The power of Spain was waning there, but she as well as Britain still claimed parts of the territory beyond the purchase. Jefferson recognized the need to explore and affirm U.S. control of the Louisiana Territory, and the purchase spurred his earlier determination to enter the struggle for the empire to its west and lay the basis for a claim.
In a broad sense, too, Jefferson was continuing the centuries-long search for a Northwest Passage to the riches of the Orientan all water or nearly all-water route from the Atlantic to the Pacific through or around northern North America that would obviate the need for U.S. and European ships to make the long voyages around South America and Africa. In 1778 the English explorer Capt. James Cook had made an inconclusive search for the passage along the Pacific coast of the continent, but in 1792-94 the Vancouver Expedition had demonstrated that for all practical purposes an all-water route through the continent did not exist. Jefferson hoped that the Lewis and Clark Expedition might still find a nearly all-water passage, but it made no such discovery.  As a matter of fact, the pathway it charted was not even economically feasible because of the long portages required and serious navigational problems.
Last Updated: 22-Feb-2004