"When the Europeans came to this continent at the end of the fifteenth century they found it already inhabited by races of men very different from themselves. These people, whom they took to calling 'Indians, ' were spread out, though very thinly, from one end of the continent to the other. Who were these nations, and how was their presence to be accounted for? To the first discoverers of America, or rather to the discoverers of the fifteenth and sixteenth centuries (Columbus and his successors), the origin of the Indians presented no difficulty. To them America was supposed to be simply an...