The Advanced Placement (AP) program stands as the foremost source of college-level academics for millions of high school students in the United States and beyond. More than 22,000 schools now participate in it, across nearly forty subjects, from Latin and art to calculus and computer science. Yet remarkably little has been known about how this nongovernmental program became one of the greatest success stories in K–12 education—until now. This book offers an account of one of the most important educational initiatives of our time. The book traces the story of AP from its mid-twentieth-century origins as a niche benefit for privileged students to its emergence as a springboard to college for high schoolers nationwide, including hundreds of thousands of disadvantaged youth. Today, AP not only opens new intellectual horizons for smart teenagers, but also strengthens school ratings, attracts topflight teachers, and draws support from philanthropists, reformers, and policymakers. At the same time, it faces numerous challenges, including rival programs, curriculum wars, charges of elitism, the misgivings of influential universities, and the difficulty of infusing rigor into schools that lack it. In today's polarized climate, can AP maintain its lofty standards and surmount the problems that have sunk so many other bold education ventures?