Titular series heroine Nancy Drew has taken up most of the scholarly attention surrounding mid-century U.S. girls’ series, and for good reason given her popularity, longevity, and feminist leanings. Since her debut in the 1930s, Nancy has been foiling criminals for nearly a century. However, Nancy and her heroics do not occur in either a publishing or a temporal vacuum. The chapters in this collection examine the narratives of series heroines that preceded and those that followed Nancy Drew, each in relation to their social, historical, and economic environments. Covering heroines including Miss Pickerell, Madge Sterling, and Polly the Powers Model, among others, this book illustrates that the recovery of stolen inheritances during the Great Depression serves different social ends than, for example, fighting Germans on an international stage. While Nancy Drew’s plotlines may have evolved alongside the changing historical context, this book invites readers to critically examine the stories of some of these other “lost” heroines of twentieth century U.S. series fiction. Organized by time period, the chapters give insight into the cultural landscape that perpetuated the popularity of these heroines in their respective eras, how these series reflected the experiences of readers across the decades, and their continued impact well into the twenty-first century.