Founded in 1944 by Helen Valentine, Seventeen magazine was the first modern “teen magazine.” An immediate success, it became iconic in establishing the tastes and behaviors of successive generation of teen girls covering the last half of the 20th century. Kelley Massoni has written the first cultural history of the origins of Seventeen and its role in shaping the modern teen girl ideal. Using content analysis, interviews, letters, oral histories, and promotional materials, Massoni is able to show how Seventeen helped create the modern concept of “teenager.” The early Seventeen provided a generation of thinking young women with information on citizenship and clothing, politics and popularity, adult occupations and adolescent preoccupations, until economic and social forces converged to reshape the magazine toward teen consumerism. A chapter on the 21st century Seventeen brings the story to the present. Fashioning Teenagers will be of interest to students of popular culture, sociology, gender studies, mass media, journalism, business, and American studies.