My research for this book could not have been possible without the generosity of John and Catherine Angle, who have supported the University of Nebraska-Lincoln Department of History for many years. John Angle died in 2008, and I will miss him dearly. His enthusiasm, good humor, and positive spirit remain an inspiration. The Angles’ support made possible much of the digital research at the heart of this book’s analysis and interpretation.

I am indebted as well to the American Council for Learned Societies for the Digital Innovation Fellowship, which I received in 2008, to the Newberry Library for a Short-Term Research Fellowship in 2007–2008, and to the British Association of American Studies for a Visiting Professorship at the Eccles Centre for American Studies at the British Library. Parts of the research were conducted with Richard Healey, University of Portsmouth, and in collaboration with him on an Economic and Social Research Council (ESRC) grant. I presented parts of this work to faculty in the History Department at the Episcopal High School in Alexandria, Virginia, where I was the Ben Geer Keys Scholar-in-Residence in 2008. I gained valuable insights from their close reading and suggestions. I also presented several chapters to the Nineteenth-Century Studies Workshop at the University of Nebraska, where I received valuable feedback from a great group of students and colleagues.

My colleagues and friends have offered cogent criticism as well as plain encouragement at nearly every stage of this project. I feel fortunate at the University of Nebraska to have such generous colleagues--Margaret Jacobs and Andrew Graybill read the entire manuscript and helped me immensely at a critical stage. Edward L. Ayers generously read an early draft of the manuscript and offered his always cogent, thoroughly encouraging, and perceptive analysis. Aaron Sheehan-Dean reviewed the manuscript with a sharp eye for both the details and the larger picture. Whatever faults are in the manuscript are mine. All of the following people have either read chapters or given me suggestions along the way: Bobby Watts, Kenneth Winkle, Andrew Graybill, Peter Maslowski, Anne Bretagnolle, Peter Onuf, Wendy Katz, Ken Price, Amy Murrell Taylor, Pete Daniel, Calvin Schermerhorn, Alice Fahs, Adam I. P. Smith, Gary Gallagher, Richard White, Douglas Seefeldt, Jeannette Jones, Alex Vazansky, John Wunder, Jane Moody, Anne S. Rubin, Tim Mahoney, James A. Rawley, Stephen Ramsay, Richard Healey, James Le Sueur, Robert Schwartz, Barbara Welke, Laura White, Tyler White, and Victoria Weoste. Students at the University of Nebraska have also given me thoughtful comments and helped research parts of this work and I wish to thank them for their spirited discussions and hard work: Nathan Sanderson, Leslie Working, Catherine Biba, Miles Krumbach, Robert Voss, Nic Swiercek, Michelle Tiedje, Kurt Kinbacher, Sean Kammer, Diane Miller, Vanessa Steinroetter, Kim Banion, and Kaci Nash. Geitner Simmons, editor of the Omaha World-Herald, a southern-history expert and modern-day Renaissance “man of letters,” generously offered to read the entire manuscript and gave me valuable advice. J. W. Kaempfer graciously helped me get settled in London for research on parts of this book, as did Father Andrew Cain, Andrew Ceresa, and Ian and Alyson Thomas.

It would be difficult to overstate how much I have benefited from the support and dedication of the Center for Digital Research in the Humanities at the University of Nebraska. This work began as an experiment in digital analysis, and the Center has shepherded for many years “the Railroads project,” as we call it. I set out to use the digital project to help me organize, arrange, make sense of, and analyze the materials of this period. C. J. Warwas, Dan Becker, Nathan Freitas, and Karin Callahan worked on the geographic information system we developed for the U.S. railroad network from 1840 to 1861, helping me not only with technical matters but also with ways to conceptualize the project. Ian Cottingham collaborated on efforts to model spatio-temporal visualization and integrate diverse data into maps. I am in their debt. Laura Weakly, Brian Pytlik-Zillig, Zach Bajabar, Keith Nickum, and Karin Dalziel each contributed their expert knowledge to the development of the Web database and archive. Trevor Munoz came on as an intern at the Center in 2009 after completing his Master’s degree in Digital Humanities at Kings College, London, and his textual analysis and concordances of The War of the Rebellion: A Compilation of the Official Records of the Union and Confederate Armies, Vol. 38, opened my eyes to new ways of thinking about these texts and about Sherman’s railroad strategy and the Atlanta Campaign. Part of any digital project entails some pure experimentation, and I am thankful that Stephen Ramsay enthusiastically collaborated on creating directed graphs of the Union commanders' "geographic vision" based on the language in their official reports. Katherine Walter and Ken Price, the co-Directors of the Center, have given me consistent encouragement and supported this research at every turn, for which I am very grateful.

Numerous archivists and librarians have also aided me in this work and generously given their time and expertise. Peterson Brink and Mary Ellen Ducey at the University of Nebraska have tirelessly worked with the remarkable Charles Kennedy railroad collection. Librarians helped me immensely in identifying new source material deep in the railroad records and in other collections, including: James Grossman, John Powell, Martha Briggs, and the staff of the Newberry Library; George Briscoe at National Archives; Greg Prickman at the University of Iowa; Sandra Treadway, Gregg Kimball, Minor Weisiger, Sara Bearss, and Brent Tartar at the Library of Virginia; Edward Gaynor, Heather Riser, and Regina Rush at the University of Virginia Albert and Shirley Small Special Collections Library; Melanie Aspey and Tracy Wilkerson at the Rothschild Archive; Moira Lovegrove and Clara Anderson at the Baring Archive; and Philip Davies and the staff of the British Library. Jean Bauer braved the backwoods of Crozet, Virginia, to locate and photograph the ruins of the Blue Ridge Tunnel for this book. I am grateful for her help.

Wendy Strothman of the Strothman Literary Agency believed in this project at its earliest stages and gave me careful suggestions throughout. My editor at Yale University Press, Christopher Rogers, deserves a thousand thanks, as does Jeffrey Schier for his thoroughly professional help in editing and production. Laura Davulis and Christina Tucker at Yale patiently advised me as I collected and arranged the images for this book. I appreciate greatly Bill Nelson's work on the maps and his almost unbelievable efficiency in producing them.

My family is at the center of my life and this book would not have been possible without their unfailing support. Heather, Sarah, Guy, Janie, Mom and Dad, Jane, cousins, and siblings have all encouraged and supported me and I am so thankful for their enthusiasm and patience.