Shortlisted for the Cundill History Prize • A Kirkus Best Nonfiction Book of the Year

“It may be the most presciently timed book ever written. . . . It's the love story between America and its secrets.” —Jon Stewart

“Connelly has defined an existential crisis: the suppression of American history. . . . The Declassification Engine makes the case that the culture of secrecy diminishes democracy. And it has now become a culture of destruction as well.” —Tim Weiner, The New York Times Book Review

“Fascinating and urgent. . . . If you believe in the founding principles of the American form of government, then the stakes could scarcely be higher.” —Patrick Radden Keefe, Foreign Affairs

“Harrowing. . . . Connelly’s book unearths disturbing tales. . . . Readers will doubtless look to The Declassification Engine to make sense of the classified files that are now in the news. Yet to insist on the timeliness of Connelly’s research may be to miss its most powerful lesson. There is a much sadder story detailed in the pages of The Declassification Engine—a story about the existential threat that secrecy poses to civic knowledge.” —The Washington Post

“Connelly has written a gripping and sobering account of the exponential increase in government secrets. He persuasively argues that the United States needs a new strategy to handle classified material, demonstrating that both our national security and the health of our democracy are at stake.” —The Christian Science Monitor

“A brilliant, deeply unsettling look at the history and inner workings of ‘the dark state.’ The number of things that truly must be kept secret is small.  The vast amount of information classified by the government is simply a means of wielding enormous power without real oversight. Again and again, Connelly reveals, secrecy has been used to hide mistakes, avoid embarrassment, cover up incompetence, and mislead the public. At a time when federal agencies are increasingly classifying or destroying documents with historical significance, this book could not be more important. An inscription at the entrance to the National Archives says it best:  ‘Eternal vigilance is the price of liberty.’ ” —Eric Schlosser, New York Times best-selling author of Command and Control

“In The Declassification Engine, Matthew Connelly provides an incisive, unexpected account of the history and practice of official secrecy, offering a glimpse into a world that truly exists in the shadows. By showing the corrosive effects of state secrecy, he successfully makes the case for a different attitude to public information.” —Anne Applebaum, New York Times best-selling author of Twilight of Democracy

“The Declassification Engine is an outstanding expose of the secrecy-industrial complex that is suffocating our democracy. Matthew Connelly describes in vivid detail how the dark state became rooted in our national-security institutions and provides common-sense prescriptions for restoring transparency.” —Craig Whitlock, New York Times best-selling author of The Afghanistan Papers

“A profoundly important work of scholarship, one that addresses core questions about American democracy and the challenges to the nation’s venerable tradition of open government. Connelly’s findings are deeply troubling but also hopeful, showing us how data science can be used to help us better understand the past and thereby point the path to a more enlightened future.” —Fredrik Logevall, Pulitzer Prize-winning author of Embers of War

MATTHEW CONNELLY is a professor of international and global history at Columbia University, codirector of its social science institute, and the principal investigator at History Lab, a project to apply data science to the problem of preserving the public record and accelerating its release. He received his BA from Columbia and his PhD from Yale. His previous publications include A Diplomatic Revolution: Algeria’s Fight for Independence and the Origins of the Post–Cold War Era and Fatal Misconception: The Struggle to Control World Population.