In 1869, having accumulated some sixteen thousand books, manuscripts, and pamphlets, besides maps and cumbersome files of Pacific Coast journals, I determined to go to work. But I soon found that, like Tantalus, while up to my neck in water, I was dying of thirst. The facts which I required were so copiously diluted with trash, that to follow different subjects through this trackless sea of erudition, in the exhaustive manner I had proposed, with but one life-time to devote to the work, was simply impracticable. In this emergency my friend, Mr Henry L. Oak, librarian of the collection, came to my relief. After many consultations, and not a few partial failures, a system of indexing the subject-matter of the whole library was devised, sufficiently general to be practicable, and sufficiently particular to direct me immediately to all my authorities on any given point. The system, on trial, stands the test, and the index when completed, as it already is for the twelve hundred authors quoted in this work, will more than double the practical value of the library. Of the importance of the task undertaken, I need not say that I have formed the highest opinion. At present the few grains of wheat are so hidden by the mountain of chaff as to be of comparatively little benefit to searchers in the various branches of learning; and to sift and select from this mass, to extract from bulky tome and transient journal, from the archives of convent and mission, facts valuable to the scholar and interesting to the general reader; to arrange these facts in a natural order, and to present them in such a manner as to be of practical benefit to inquirers in the various branches of knowledge, is a work of no small import and responsibility. And though mine is the labor of the artisan rather than that of the artist, a forging of weapons for abler hands to wield, a producing of raw materials for skilled mechanics to weave and color at will; yet, in undertaking to bring to light from sources innumerable essential facts, which, from the very shortness of life if from no other cause, must otherwise be left out in the physical and social generalizations which occupy the ablest minds, I feel that I engage in no idle pastime. A word as to the Nations of which this work is a description, and my method of treating the subject. Aboriginally, for a savage wilderness, there was here a dense population; particularly south of the thirtieth parallel, and along the border of the ocean north of that line. Before the advent of Europeans, this domain counted its aborigines by millions; ranked among its people every phase of primitive humanity, from the reptile-eating cave-dweller of the Great Basin, to the Aztec and Maya-Quiché civilization of the southern table-land,--a civilization, if we may credit Dr Draper, "that might have instructed Europe," a culture wantonly crushed by Spain, who therein "destroyed races more civilized than herself."