In conformity to the act of Congress of the United States, entitled "An act for the encouragement of learning, by securing the copies of maps, charts, and books, to the authors and proprietors of such copies during the times therein mentioned." And also to the act, entitled, "An act supplementary to an act, entitled, "An act for the encouragement of learning, by securing the copies of maps, charts, and books, to the authors and proprietors of such copies during the times therein mentioned," and extending the benefits thereof to the arts of designing, engraving, and etching historical and other prints." DAVID CALDWELL, Clerk of the District of Pennsylvania. PREFACE. In presenting these volumes to the public, the editor owes equally to himself and to others, to state the circumstances which have preceded the publication, and to explain his own share in compiling them. It was the original design of captain Lewis to have been himself the editor of his own travels, and he was on his way towards Philadelphia for that purpose when his sudden death frustrated these intentions. After a considerable and unavoidable delay, the papers connected with the expedition were deposited with another gentleman, who, in order to render the lapse of time as little injurious as possible, proceeded immediately to collect and investigate all the materials within his reach. Of the incidents of each day during the expedition, a minute journal was kept by captain Lewis or captain Clark, and sometimes by both, which was afterwards revised and enlarged at the different periods of leisure which occurred on the route. These were carefully perused in conjunction with captain Clark himself, who was able from his own recollection of the journey, as well as from a constant residence in Louisiana since his return, to supply a great mass of explanations, and much additional information with regard to part of the route which has been more recently explored. Besides these, recourse was had to the manuscript journals kept by two of the serjeants, one of which, the least minute and valuable, has already been published. That nothing might be wanting to the accuracy of these details, a very intelligent and active member of the party, Mr. George Shannon, was sent to contribute whatever his memory might add to this accumulated fund of information.