All men have, or ought to have, some peculiar ambition towards the attainment of which the principal energies of their lives are directed: mine, which developed itself some thirty years since, has been that of perpetuating the looks and customs of a numerous race of human beings fast passing to extinction. In this pursuit I have passed fourteen years of my life amongst the various tribes of Indians in North, South, and Central America, and of the numerous customs which I have recorded, there is nothing else so peculiar and surprising as the O-kee-pa of the Mandans, the subject of this book, — an annual ceremony, which I described in a former publication, but which description, forming hut an item in a largo work, was necessarily too brief to give all the connecting links of a custom which derives its interest from being understood in all its phases.<br><br>This publication, therefore, which is made for all classes of readers, as well as for gentlemen of science who study, not the proprieties of man, but Man, and which has not before appeared in all its parts, is made from a sense of duty, to perpetuate entire a human custom of extraordinary interest, peculiar to a single tribe in America, and which tribe, as will be seen, is now extinct; leaving in my hands alone chiefly, what has been preserved of their personal looks and peculiar modes.