Many people have given assistance and encouragement during the research for this book. The sum of their contributions has made it possible.

Manly P. Hall, President and Founder of the Philosophical Research Society, encouraged this work, and generously allowed me to work with and print the Le Plongeon glass negatives.  His staff, including librarian Pearl Thomas, and assistant Edith Waldron, were always ready to locate obscure articles and materials in the Society's collections.

Other assistance with Le Plongeon's collections of photographs came from photographer, Ansel Adams, Pirkle Jones at the San Francisco Art Institute, Richard F. Carter, Ralph E. Black, and Larry Harwood of the University of Colorado.

At a crucial moment early in my delvings into Augustus Le Plongeon, Linnea Wren had the good sense to steer me into Gordon Willey's office.  He encouraged me to continue, and expand my research perspective since he felt Le Plongeon's work deserved a closer look.

Field work in Yucatan was facilitated by archaeologists Norberto Gonzales C., and Peter Schmidt of the Instituto Nacional de Antropologia e Historia, and by Susan Milbrath of the Florida State Museum.

A number of institutions and individuals were of great help with archival research.  Sincere thanks to Sally L. Bond, Ian Graham and Daniel W. Jones, Jr., of the Peabody Museum of Archaeology and Ethnology, Harvard University; Gordon F. Ekholm, American Museum of Natural History; M. J. De La Haye of the Societe Jersiaise; William Joyce, American Antiquarian Society; Thomas Niehaus, Latin American Library of Tulane University; Franklin Portugal, Carnegie Institution of Washington;  Diane Trubandt, John Q. Packard Library in Marysville, California; the staffs of the Albany Institute of History and Art in New York, Bancroft Library of the University of California in Berkeley, the Bibliotheque Nationale in Paris, the Brooklyn Museum, California Academy of Sciences in San Francisco, l'Ecole Polytechnique of Paris, the Long Island Historical Society, the Metropolitan Museum of Art,the Merman Church's Genealogical Research Department, Musee de l'Homme in Paris, and the Smithsonian Institution.

Many individuals assisted by providing information, encouragement, or comments on the manuscript.  Their invaluable help is gratefully acknowledged.  They include George Andrews, Anthony Aveni, Elizabeth Baquedano, Cara Billot, Jacques Barchalon, David Carrasco, David and Vilma Casares, Curtis M. Hinsley, Jr., A. F. C. Jackson, A. A. Keim, Frank Le Maistre, Keith McElroy, Russ McGoodwin, Barbara McLeod, Susan Milbrath, A. E. Mourant, Donald Patterson, Ross Parmenter, Dorie Reents, Linda Schele, George Stuart, John Weeks, Shelley Vaughan Williams, and David and Linnea Wren.

The support and interest of the staff at the University of New Mexico Press has been extremely important.  Former Director Luther Wilson, Director Beth Hadas, and Editor Claire Sanderson have all played a vital roll.

Archaeologist Skip Messenger, who patiently put up with the "Old Doctor's" long intrusion into his household, provided his artistic skills.  His maps and drawings from the Le Plongeons' mural tracings are an important contribution to the aesthetics of the book.

Lawrence G. Desmond