This book contains a comprehensive analysis trying to identify all American women studying mathematics and obtaining their PhDs before 1940 (the first woman graduated at the University of Columbia in 1886). Thanks to extensive archival studies, 228 women receiving their PhDs from US institutions or US-born women receiving their degrees abroad have been identified. In the first part of the book (pages 1-118), the authors have presented an introductory essay trying to reconstruct a picture of the women's group in the American mathematical community as completely as possible and to describe their roles in the large scientific and cultural communities. In the second part of the book (pages 119-322), the authors gather biographical and bibliographical information on each of these more than two hundred women. They describe their family backgrounds, education, careers, professional activities and recognition. They also identify each woman's publications, teaching activities, professional presentations and research contributions to mathematics or to industry. At the end of the book, the authors include a list of archives and manuscript collections that were used in the preparation of the biographical entries (pages 325-331). They also add a large biography containing primarily those items that have relevance for the essay (pages 333-337). The book can be recommended to researchers, teachers and students in mathematics, the history of mathematics, the history of science, sociology and gender studies. The material included in the book will stimulate additional studies, analysis and research.