Perhaps Putnam’s most important book, this one begins with the observation that the United States today closely mirrors the Gilded Age of the late nineteenth century—a time of deep political divisions, mistrust and cynicism, enormous economic inequality, racial segregation, corporate monopolies, and cultural narcissism. Spurred by the Progressive movement, the country then embarked on momentous reforms that in the seven decades that followed pushed American society in a more communitarian and less individualistic direction. In the middle of the 1960s, these economic, political, and social trends suddenly reversed, setting in motion a steep societal decline that continues today. The authors call the arc of this history the “I-we-I” curve and hope for another upswing now. There are countless stirring insights in this book. Putnam and Romney Garrett range with ease across history, political science, economics, and social science, distilling masses of complex data into simple graphs that are integrated seamlessly into the fluid prose. The authors do disappoint a little in finding only weak lessons from this history that might spark a second communitarian upswing today.