Coming as it does during a global pandemic and domestic political chaos, John Howard Smith’s A Dream of the Judgment Day is a timely reminder of just how deeply embedded are the twin themes of apocalypticism and millennialism in the American narrative. From the QAnon cult to antivaxxers, we have all witnessed how easily apocalyptic rhetoric has been used to mobilize segments of the population to levels of direct action rarely seen in recent memory. Given that Smith began his project some twenty years before, the book’s increased salience is fortuitous of course, but neatly underscores its need. The author’s original goal was simply to chart how “the prevalence of Enlightenment-oriented, optimistic, postmillennialism slowly and steadily gave way to pessimistic, bibliocentric, ‘fundamentalist’ premillennialism” (275). A Dream of the Judgment Day accomplishes this in admirable detail, but the very comprehensiveness of Smith’s approach leads him well beyond the evangelical mainstream. A significant amount of the book explores the impact of these twin eschatological themes on new religious movements, African American Christianity, Native American revitalization movements, and, to some degree, popular and political culture.Although Smith proceeds chronologically, the book is perhaps best evaluated topically. After brief introductory chapters defining apocalypticism and millennialism and discussing their origins in the religions of the Near East, most of the chapters concern the development of Protestant apocalypticism in America from the colonial period to the Gilded Age—in other words, from the Puritans to the Fundamentalists. Much of this is familiar territory, and the author dutifully charts the influence of apocalypticism on such events as the Great Awakenings, the French and Indian War, the Revolutionary War, and the Civil War. What is distinctive here is the author’s judicious use of texts both well-known and obscure, and his attention to both elite and nonelite voices, especially those of women, African Americans, and Native Americans. Smith is also attentive to the ongoing transatlantic aspects of Protestant apocalypticism throughout the period, as well as recognizing its national pervasiveness beyond the Northeast, which is typically privileged in discussions of this topic. Finally, the author highlights the constant interplay between pre- and postmillennial interpretations of America’s destiny, the agonistic oscillation of which has been a key component of the nation’s political and culture wars from the colonial period to the present.Throughout the volume, Smith makes the distinction between horizontal and vertical apocalypses, using apocalypse in its original Greek sense, “to reveal that which is hidden” (xvi). Horizontal refers to visionary experiences that reveal the events leading to the end of the world, while vertical refers to experiences of God and heaven, which typically authorize the former. With the lifting of institutional restraints on such experiences in the wake of the Reformation, countless visionary prophets promoted new combinations of horizontal/vertical apocalypses leading to a wide variety of new sectarian groups. Nowhere was this process more evident than in North America, where the democratization of Christianity encouraged radical experimentation in this regard. Students of new religious movements will therefore find this book useful because Smith devotes a great deal of space to exploring the varieties of apocalyptic sectarianism in the United States—from well-known groups such as the Mormons, Seventh-day Adventists, and Oneida Perfectionists to the lesser-known, such as the City Hill community of the “Publick Universal Friend,” Jemima Wilkinson, and the Koreshan Unity of Cyrus Teed. Smith also points out the constant cross-fertilization of such movements, highlighting, for example, the tremendous influence of Shaker apocalypticism on American new religious movements far and wide.One unique aspect of A Dream of the Judgment Day is the close examination Smith gives to the apocalyptic and millennial elements of Native American revitalization movements. Beginning with the various indigenous prophets that arose during the colonial period among the Eastern Woodland peoples, Smith traces the key role apocalyptic ideologies played in resisting white settler violence all the way up to the Wounded Knee massacre in 1890. Again, in addition to such well-known prophets as Neolin, Tenskwatawa, and Smohalla, Smith also discusses lesser-known figures such as the Wyoming Woman and Kenekuk, all in order to emphasize the diversity of indigenous apocalyptic thought.Although library shelves are already heavy with good academic studies of American apocalypticism, John Howard Smith’s A Dream of the Judgment Day is, in my opinion, the best single volume on the history of apocalypticism and millennialism in the United States now available. It will serve not only as an excellent introduction to graduate students who wish to do research on these topics, but also as an up-to-date reference work for scholars working in American religious history, new religious movements, and African American and Native American studies.