In this “fascinating” ( ) narrative, Michael Kazin brings us into the ranks of one of the largest, most diverse, and most sophisticated peace coalitions in US history. The activists came from a variety of backgrounds: wealthy, middle, and working class; urban and rural; white and black; Christian and Jewish and atheist. They mounted street demonstrations and popular exhibitions, attracted prominent leaders from the labor and suffrage movements, ran peace candidates for local and federal office, met with President Woodrow Wilson to make their case, and founded new organizations that endured beyond the cause. For almost three years, they helped prevent Congress from authorizing a massive increase in the size of the US army—a step advocated by ex-president Theodore Roosevelt. When the Great War’s bitter legacy led to the next world war, the warnings of these peace activists turned into a tragic prophecy—and the beginning of a surveillance state that still endures today. Peopled with unforgettable characters and written with riveting moral urgency, is a “fine, sorrowful history” ( ) and “a timely reminder of how easily the will of the majority can be thwarted in even the mightiest of democracies” ( ).