students of the republic both Mexican and foreign. From neither of these sources alone nor by both together is a satisfactory picture of Mexican conditions derivable, and at many points the testimony of periodicals and of residents of the republic must be accepted as the best information available. This is true especially for recent years, but in a measure also in discussing the earlier periods, for the formal history of Mexico, economic, political and social, is to an unusual degree unwritten.
My thanks are due to the authorities of the University of California and to those of the Library of Congress at Washington for facilities placed at my disposal. I am indebted also to friends too numerous to mention for suggestions and criticism, to Dr. Norman Bridge, who has read the manuscript, and to Mr. Edward L. Doheny, whose establishment of the Doheny Foundation made available valuable source materials relating to Mexican-American relations.
