As in editing Lewis and Clark, so in working upon Pike, I have been encouraged and assisted by many friends, not all of whom have I the pleasure of knowing personally. I am under special obligations to Mr. Alfred J. Hill of St. Paul, Minn., whose knowledge of the history and geography of the Upper Mississippi region is not less accurate than extensive. Mr. Hill has been good enough to accompany me throughout Pt. 1 of the work, and give me the benefit of his close scrutiny of the press-proofs, in the form of constant suggestion and criticism, besides frequent references to other available sources of information which I might have overlooked. His valued co-operation to this extent increases very appreciably the confidence which the reader may feel in all that relates to the Mississippi Voyage.[NP-1] Mr. R. I. Holcombe, county historian of Missouri, now of the U. S. Marshal's office in St. Paul, has criticised those pages of Pt. 2 which relate to the Osage river. The same friendly attentions have been bestowed upon the whole of Pike's route in Colorado by Mr. Wm. M. Maguire of Denver; and upon various points concerning the pueblos of New Mexico and Arizona, by Mr. F. W. Hodge of the U. S. Bureau of Ethnology. Hon. J. V. Brower of St. Paul, Commissioner of the Itasca State Park, has made me free to use his map of the park in connection with the new historico-geographical chart of the Upper Mississippi. The Hon. the Secretaries of War and of State have granted permission to examine official archives of their respective Departments; this research, in the War Department, has been facilitated by Mr. John Tweedale, Chief Clerk, and Mr. David Fitz Gerald, Librarian; in the State Department, by Mr. W. W. Rockhill, Chief Clerk; Mr. Andrew H. Allen, Chief of the Bureau of Rolls and Library, and Mr. Walter Manton of the same Bureau. Gen. A. W. Greely, Chief Signal Officer, U. S. Army; Gen. T. L. Casey, late Chief of Engineers, U. S. Army, and Mr. W. W. Winship, Chief Draughtsman of the same; Major J. W. Powell, late Director of the U. S. Geological Survey, and Director of the Bureau of Ethnology, Smithsonian Institution; Mr. Henry Gannett and Mr. A. H. Thompson of the same Survey; Prof. G. Brown Goode, Director of the U. S. National Museum, and Prof. Otis T. Mason of that Museum; Prof. Harry King, of the U. S. General Land Office; Hon. D. M. Browning, Commissioner of Indian Affairs, and Mr. R. F. Thompson of the same Bureau; Mr. L. O. Howard, Chief of the Division of Entomology of the U. S. Department of Agriculture; Mr. A. R. Spofford, Librarian of Congress; Prof. N. H. Winchell, Director of the Geological Survey of Minnesota; Hon. Charles Aldrich, Curator of the Iowa State Historical Department; Mr. R. G. Thwaites, Secretary of the Historical Society of Wisconsin; Mr. D. L. Kingsbury, Acting Secretary of the Historical Society of Minnesota; Hon. C. C. James, Deputy Minister of Agriculture of Ontario, and Hon. A. Blue of the Bureau of Mines of Ontario, have each rendered valued official or personal favors, or both. I am also indebted in various ways, most of which are indicated in their respective connections in the course of my notes, to ex-President Benjamin Harrison; Mr. W. H. Harrison of North Bend, O.; Mrs. B. H. Eaton of El Paso, Tex.; Governor A. W. McIntire of Colorado; R. T. Durrett, LL. D., of Louisville, Ky.; Prof. E. D. Cope of Philadelphia; Mr. James Bain, Jr., of the Public Library of Toronto; Mr. L. P. Sylvain, Assistant Librarian of Parliament, Ottawa; Lieutenant J. R. Williams of the Third Artillery, U. S. A.; Lieutenant H. M. Chittenden of the Corps of Engineers, U. S. A.; Rev. O. S. Bunting of Trenton, N. J.; Prof. J. D. Butler of Madison, Wis.; Mr. W. P. Garrison of the New York Nation; Judge Thos. H. Bacon of Hannibal, Mo.; Judge Nathan Richardson of Little Falls, Minn.; Mr. Charles Hallock of Hallock, Minn.; Mr. H. D. Harrower of New York, N. Y.; Mr. T. H. Lewis of St. Paul, Minn.; Mr. C. H. Small of Pueblo, Col.; Mr. Geo. R. Buckman of Colorado Springs, Col.; Mr. D. Bosse of Great Bend, Kas., and Mr. Luther R. Smith of Washington, D. C. Mrs. Mary B. Anderson of Washington, D. C., has taken great pains in preparing under my direction an index, of somewhat unusual extent and special difficulty, which I am led to believe will be found exceptionally accurate. Mr. Robert M. Trulan and Mr. H. E. Gore-Kelly of the Mershon Printing Company, Rahway, N. J., have read the proofs with untiring zeal as well as professional skill. Mr. Francis P.