Competition around U.S. college admissions, particularly at the most selective colleges and universities, has never been greater, and recent research suggests that where one attends college matters in terms of persistence, graduation, and future opportunities. In this high-stakes environment, parents and students in affluent secondary schools approach preparation for selective admissions as an “arms race,” seeking out opportunities and experiences to differentiate themselves from the rest of college applicants. Drawing upon ethnographic data collected from a purposefully selected tri-school sample of students, parents, and school personnel, Class Warfare peers underneath the “sacred moment” of the college admissions process, offering a worm's eye view of the day-to day and week-by-week struggles over class positioning as engaged by differentially located class and race actors in public and private privileged secondary schools in early 21st century United States. The college admissions process represents the culmination of intentionally waged “class work” that is linked to an envisioned battleground over forms of privilege represented by admission to particular kinds of postsecondary destinations. Class Warfare details the extent to which and the ways in which parents, school counselors, teachers, and students at three iconic, privileged, secondary schools in the United States work to “lock in” the next generation's privileged class status via the postsecondary admissions process, illuminating the ways in which sector of secondary school, student position in the opportunity structure of the school, and degree of parent/student closeness to the habitus embedded within particularly located privileged institutions shape “class work” and future class structure.