The staff of the Research Library of Sir John Soane Museum made several summer days spent in the library’s collections enormously helpful. I am grateful to the librarian, Dr. Stephanie Coane; Stephen Astley, drawings curator; the head of library services, Susan Palmer; and Bellina Adjei, who expertly handled permissions. At the Pennsylvania State Archives, I benefitted greatly from the expertise of Associate Archivist Michael D. Sherbon, who helped me locate images of the Camelback and Dunlap’s Creek bridges.
I was able to review the papers of the late J. G. James, the world’s foremost student of early iron bridges, at the Institution of Civil Engineers in London. I am grateful to the institute’s librarian, Debbie Francis, for providing me access to these and other invaluable materials.
Ms. Polly Munson of Peyton, Colorado, contacted me some years ago about a brief piece I wrote on Paine for the online journal Common-Place. She is a descendant of John Hall and came into possession of his letter books, which she has carefully transcribed and which, to my great benefit, she very generously shared with me.
James N. Green, librarian of the Library Company of Philadelphia, very kindly granted me access to the John Hall Diaries and fielded numerous obscure queries with his customary good humor. Rob Karnowski, a graduate student Florida State University, did yeoman’s work, transcribing sections of the Hall Diaries. David Brackett, another descendant of John Hall, shared with me his encyclopedic knowledge of his ancestor’s biography. Andrew McCarthy, a brilliant undergraduate at Florida State University, spent a summer expertly checking citations and sharing with me his extensive knowledge of eighteenth-century architecture.
My agent, Lisa Adams of the Garamond Agency, has been an utterly indispensable source of encouragement and wise counsel. At W. W. Norton, I have had the great privilege of working with Steve Forman, a master of the editor’s craft. Steve’s editorial assistant, Travis Carr, has helped in innumerable ways. I am also grateful for Trent Duffy’s exceptionally careful copyediting.
Two friends—Jane Kamensky and Ray Raphael—read an early draft and helped me find my way to the story I was trying to tell.
For everything else, thanks especially to Stacey Rutledge.