I have drawn heavily on others who have written in this field--Andrews,
Beard, Paxson and Peck, and especially on the volumes written for the
American Nation series by Professors Dunning, Sparks, Dewey, Latane
and Ogg. Haworth's _United States in Our Own Time, 1865-1920_, was
unfortunately printed too late to give me the benefit of the author's
well-known scholarship. Many friends have generously assisted me. My
colleagues, Professors F.A. Updyke, C.A. Phillips, G.R. Wicker, H.D.
Dozier, and Malcolm Keir have read the manuscript of individual
chapters. Professor E.E. Day of Harvard University gave me his counsel
on several economic topics. Professor George H. Haynes of the Worcester
Polytechnic Institute, Professor B.B. Kendrick of Columbia University,
Professor W.T. Root of the University of Wisconsin, and Professors L.B.
Richardson and F.M. Anderson of Dartmouth College have read the entire
manuscript. Officials at the Dartmouth College Library, the Columbia
University Library, and the Library of Congress gave me especial
facilities for work. Two college generations of students at Dartmouth
have suffered me to try out on them the arrangement of the chapters as
well as the contents of the text. Harper and Bros. allowed me to use a
map appearing in Ogg, _National Progress_, and D. Appleton and Co. have
permitted the use of maps appearing in Johnson and Van Metre,
_Principles of Railroad Transportation_; A.J. Nystrom and Co. and the
McKinley Publishing Co. have allowed me to draw new maps on outlines
copyrighted by them. At all points I have had the counsel of my wife
and of Professor Max Farrand of Yale University.

CHARLES R. LINGLEY.
Dartmouth College, June 14, 1920.