This dissertation examines the discursive construction of the trope of the ideal girl in popular American girls' series in the twentieth century. Girls' cultural artifacts, including girls' literature series, provide sites for understanding girls' experiences and exploring girlhood itself as a socially constructed identity, yet are often overlooked due to their presumed insignificance. Simple dismissal of these texts ignores the weight of their popularity and the processes through which they reach such status. This project challenges the derisive attitude towards girls' culture and begins with the assumption that these cultural texts do ideological work and therefore require consideration. The dissertation traces the development of the ideal and non-ideal girl over time, taking into account the cultural, political, and economic factors that facilitate the production of the discourses of girlhood. I include analysis of texts from six popular American girls' series as primary texts; visual elements or media productions related to the series; and supporting historical documents such as newspapers, "expert" texts, popular parents' and girls' magazines, film; and advertising. Methodological approach incorporates elements of literary criticism and discourse analysis, combining literary, historical, and cultural approaches to primary texts and supporting documents to trace the moments of production, resistance, and response in the figure of the ideal girl. Throughout the project, I pay particular attention to the intersections of race, class, gender, sexuality, and nationality in the figure of the ideal girl and her non-ideal counterparts. I argue that girls' series, slipping under the radar as a denigrated cultural medium, capture and perpetuate cultural anxieties around heterosexuality, whiteness and American identity, appropriate gender roles, and class mobility. These texts discipline the non-ideal girl toward the ideal, always with the expectation of failure.