In putting together this book I worked under the shadow of great travelers, scientists, and historians ranging from William H. Prescott, Francis Parkman, and John Lloyd Stephens in the nineteenth century to (I cite only a sampler) William Cronon, Alfred W. Crosby, William M. Denevan, Francis Jennings, John Hemming, Claude Lévi-Strauss, Roderick Nash, and Carl Sauer in the twentieth and twenty-first. The comparison is daunting. Luckily, I have been able to benefit from the advice, encouragement, and criticism of many scholars, beginning with Crosby and Denevan themselves. A number of researchers read the draft manuscript in part or whole, a great kindness for which I thank Crosby, Denevan, William Balée, Clark Erickson, Susanna Hecht, Frances Karttunen, George Lovell, Michael Moseley, James Petersen, and William I. Woods. Although they helped me enormously, the book is mine in the end, as are its remaining errors of fact and balance.

I am grateful to all the researchers who were kind enough to put aside their doubts long enough to help a journalist, but in addition to those mentioned above I would especially like to thank—for favors, insights, or just the gift of time—Helcio Amiral, Flavio Aragon Cuevas, Charles Clement, Michael Crawford, Winifred Creamer, Vine Deloria Jr., Henry F. Dobyns, Elizabeth Fenn, Stuart Fiedel, Susan deFrance, Jonathan Haas, Susanna Hecht, Charles Kay, Patricia Lyon, Beata Madari, David Meltzer, Len Morse-Fortier, Michael Moseley, Eduardo Neves, Hugo Perales, Amado Ramírez Leyva, Anna C. Roosevelt, Nelsi N. Sadeck, the late Wim Sombroek, Russell Thornton, Alexei Vranich, Patrick Ryan Williams, and a host of Bolivian, Brazilian, Canadian, Mexican, and U.S. graduate students. My gratitude to the editors of the magazines in which bits of 1491 first appeared: Corby Kummer, Cullen Murphy, Sue Parilla, Bill Whitworth, and the late Mike Kelly at The Atlantic Monthly; Tim Appenzeller, Elizabeth Culotta, Colin Norman, and Leslie Roberts at Science; David Shipley and Carmel McCoubrey at the New York Times; Nancy Franklin at Harvard Design Magazine; and George Lovell at Journal of the Southwest.

For library access, travel tips, withering critiques, friendly encouragement at psychologically critical times, and a daunting list of other favors I owe debts to Bob Crease, Josh D’Aluisio-Guerreri, Dan Farmer (and all the folks on the listservs), Dave Freedman, Judy Hooper, Pam Hunter (and Carl, too, of course), Toichiro and Masa Kinoshita, Steve Mann, Cassie Phillips, Ellen Shell, Neal Stephenson, Gary Taubes, Dick Teresi, and Zev Trachtenberg. Newell Blair Mann was a boon traveling companion in Bolivia and Brazil; Bruce Bergethon indulged me by coming to Cahokia; Peter Menzel went with me to Mexico four times. Jim Boyce helped get me to Oaxaca and CIMMYT. Nick Springer provided a design for the rough maps that Tim Gibson and I put together. Stephen S. Hall was really, really patient and really, really helpful about the immune system. Ify and Ekene Nwokoye tried at various times to keep me organized. Brooke Childs worked on photo permissions. Mark Plummer provided me with far too many favors to list. The same for Rick Balkin (the fifth book for which he has done so). June Kinoshita and Tod Machover allowed me to finish Chapter 4 in their carriage house in Waltham. My deepest gratitude to Faith D’Aluisio and Peter Menzel, who let my family and me stay in their guesthouse in Napa, where Chapters 6 through 8 emerged into the world. Caroline Mann read an early draft and provided many useful comments. Last-minute help from Dennis Normile and the Foreign Correspondents Club of Tokyo is hereby recognized and thanked.

I am lucky in my publishers, Knopf in the United States and Granta in the United Kingdom. In this, our third book together, Jon Segal at Knopf demonstrated his mastery of not only the traditional pencil skills of the classic editor but also the new techniques the times require to send a book on its way. In addition, I must doff my beret in Borzoi land to Kevin Bourke, Roméo Enriquez, Ida Giragossian, Andy Hughes, and Virginia Tan. At Granta, Sara Holloway gave excellent advice and tolerated repeated auctorial meddling and procrastination. So many other people in so many places pulled strings on my behalf, tolerated repeated phone calls, arranged site visits, edited or checked manuscripts, and sent me hard-to-find articles and books that I could not possibly list them all. I hope that in the end this book seems to them worth the trouble.

If you find an error please notify us in the comments. Thank you!