So far as the author knows there is no published study which discusses in detail the important business problems connected with the history of the Southern Pacific Railroad lines. Most of the books which contain references to the Southern Pacific or to the Central Pacific limit themselves to a few chapters upon the romantic aspects of their construction. The few works which treat of the later period confine themselves chiefly to particular episodes in Southern Pacific history, often with the deliberate attempt to discredit the railroad company. The truth is that most writers upon the Southern Pacific have relied upon the reports of the United States Pacific Railway Commission or on BancroftÕs ÒHistory of California,Ó and very few have done original work from source material. Yet the usable material dealing with the subject of Pacific railroads is abundant. The Southern Pacific has left a broad trail in California. The record of its doings is to be found in court reports; in state, city, and federal records; in the public testimony, or still better, in the private letters of owners or managers of company enterprises; in the reports of the company itself and of its engineers or other representatives; in pamphlets without number; in files of newspapers. It is true that much of the data is partisan and unreliable as to details. Yet a partisan statement is serviceable if one knows it to be partisan, and, if one has reliable information with which to check the unreliable, the extent of partisan exaggeration in a given case becomes itself a fact of no insignificant importance. Most of the documents used in the following pages have been consulted in one or another of three large collections: that of the Bancroft Library of the University of California; that of the HopkinsÕ Railway Library of Stanford University; and that of the State Library at Sacramento. Use has also been made of data in the office of the Secretary of State of California and of the State Railroad Commission. In certain cases the manuscript has been submitted to officials of the Southern Pacific Company for their comment, or to shippers or business men who were believed to be well-informed. The work has been more or less actively in progress over a period of eight years so that there has been more than usual opportunity for checking, comparison of views, and the testing of material. It is the authorÕs hope that he has at least examined all the significant classes of information on the particular subjects which he has discussed. With a subject so extensive it is rarely, if ever, possible to reach all the fugitive literature, or to consult all the living men from whom opinions or scraps of information might be obtained. The most that can be said is that there has been a diligent search, with good facilities, through a number of years.