In all the territorial subdivisions, southern as well as northern, I treat the beginnings and earliest development more exhaustively than later events. After the Conquest, the histories of Central America and Mexico are presented on a scale sufficiently comprehensive, but national rather than local. The northern Mexican states, having had a more varied experience, arising from nearer contact with progressional events, receive somewhat more attention in regard to detail than other parts of the republic. To the Pacific United States is devoted more space comparatively than to southern regions, California being regarded as the centre and culminating point of this historical field. * * * * * For the _History of Central America_, to which this must serve as special as well as general introduction, I would say that, besides the standard chroniclers and the many documents of late printed in Spain and elsewhere, I have been able to secure a number of valuable manuscripts nowhere else existing; some from the Maximilian, Ramirez, and other collections, and all of Mr E. G. Squier's manuscripts relating to the subject fell into my hands. Much of the material used by me in writing of this very interesting part of the world has been drawn from obscure sources, from local and unknown Spanish works, and from the somewhat confused archives of Costa Rica, Honduras, Nicaragua, Salvador, and Guatemala. Material for the history of western North America has greatly increased of late. Ancient manuscripts of whose existence historians have never known, or which were supposed to be forever lost, have been brought to light and printed by patriotic men and intelligent governments. These fragments supply many missing links in the chain of early events, and illuminate a multitude of otherwise obscure parts. My efforts in gathering material have been continued, and since the publication of _The Native Races_ fifteen thousand volumes have been added to my collection. Among these additions are bound volumes of original documents, copies from public and private archives, and about eight hundred manuscript dictations by men who played their part in creating the history. Most of those who thus gave me their testimony in person are now dead; and the narratives of their observations and experiences, as they stand recorded in these manuscript volumes, constitute no unimportant element in the foundation upon which the structure of this western history in its several parts must forever rest. * * * * *