288 IMPORTANCE OF THE DISCOVERIES. [1806. 



stream, and descended it to the Missouri, where they joined Lewis 

 and his men on the 12th of August. 



From the point of confluence of the two rivers, the whole body 

 moved down the Missouri ; and, on the 23d of September, 1806, 

 they arrived in safety at St. Louis, having travelled, in the course 

 of their expedition, more than nine thousand miles. 



The preceding sketch of the long and difficult expedition of 

 Lewis and Clarke will serve to show the general course of their 

 routes between the Mississippi and the Pacific. As to the priority 

 and extent of their geographical discoveries, a few words will 

 suffice. The Missouri had been ascended, by the French and 

 Spanish traders, to the mouth of the Yellowstone, long before 

 Lewis and Clarke embarked on it ; but ample proofs are afforded, 

 by the maps drawn prior to their expedition, that no information 

 even approximating to correctness had been obtained respecting the 

 river and the countries in its vicinity. With regard to the territory 

 between the great Falls of the Missouri and those of the Columbia, 

 and the branches of either river joining it above its falls, we have 

 no accounts whatsoever earlier than those derived from the journals 

 of the American exploring party. The Tacoutchee-Tessee, navi- 

 gated by Mackenzie in 1793, and supposedly him to be a branch 

 of the Columbia, was afterwards discovered to be a different stream, 

 now called Preiser's River, emptying into the Strait of Fuca ; and 

 no evidence has been adduced of the passage of any white person 

 through the country between the Rocky Mountains and the Pacific, 

 north of California, from the time of Mackenzie's journey to that 

 of the expedition of Lewis and Clarke.* 



Politically, the expedition was an announcement to the world of 

 the intention of the American government to occupy and settle the 

 countries explored, to which certainly no other nation except Spain 

 could advance so strong a claim on the grounds of discovery or of 

 contiguity ; and the government and people of the United States 

 thus virtually incurred the obligation to prosecute and carry into 



* The journal of the expedition of Lewis and Clarke was not published until 1814, 

 when it appeared nearly in the same state in which it came from the hands of Lewis, 

 shortly before the melancholy termination of his existence. It affords abundant proofs 

 of the powers of observation possessed by those who were engaged in the enterprise; 

 and the mass of facts, geographically, commercially, and politically important, which 

 it contains, causes it still to be regarded as the principal source of information respect- 

 ing the geography, the natural history, and the aboriginal inhabitants, of the portions 

 of America traversed by the Missouri and the Columbia. 



