In this fully updated second edition of their masterful history, leading historians and best-selling authors Kevin M. Kruse and Julian E. Zelizer uncover the origins of our current moment, answering the question: When--and how--did America become so polarized? It all starts in 1974 with the Watergate crisis, the OPEC oil embargo, desegregation, busing riots in Boston, and the wind-down of the Vietnam War. What follows is the story of our own lifetimes. It's the story of ever-widening historical fault lines over economic inequality, race, gender, and sex norms firing up a polarized political landscape. It is also the story of the profound transformations of the media and our political system fueling the fire. The new edition includes a brand-new chapter, "American Carnage," on the Trump administration; a new epilogue on the Biden administration and the 2024 general election; and significant updates throughout.