The authors are deeply appreciative of the contributions of the many individuals and institutions to the preparation of this volume. We are particularly obligated to the members of the Petroleum History Committee appointed by the American Petroleum Institute, who, under the chairmanship of Stanton K. Smith, co-operated with Northwestern University in making this study possible. Dr. John W. Frey, who served as secretary of the Petroleum History Committee, was most helpful in supplying source materials and offering constructive suggestions at all stages in the preparation of the manuscript. James E. Moss, director of the A.P.I.'s Division of Transportation in Washington, D. C., generously lent us many items from his personal collection of documents covering early phases of the industry's history. William B. Harper, director of economic information for the A.P.I., also supplied us with valuable statistical data.
We are heavily indebted to the directors and staff members of various public, company, and university libraries for their willingness to lend us materials and documents dealing with the history of petroleum. Those who were especially co-operative included Miss Virginia Smythe, of the A.P.I. library in New York City; Mrs. Carol M. Cronkhite at the New York Public Library; M. P. Doss, of the Texas Company; William Wright, of the University of Pennsylvania Library; James Stevenson, director, and T. J. Garvin, curator of the Drake Museum at Titusville; Miss Bess Glenn and John E. Maddox, of the National Archives; John P. McGowan, librarian of the Technological Institute, Northwestern University; and Miss Marjorie Carpenter, Miss Aleen Baker, and Miss Mary L. Hilton, staff members of the Deering Library, Northwestern University.