Gladys Tantaquidgeon's A Study of Delaware Indian Medicine Practice and Folk Beliefs is a landmark in Native American ethnobotany and cultural preservation. A Mohegan anthropologist and medicine woman herself, Tantaquidgeon offers a rare insider's account of the spiritual and medicinal traditions of the Delaware (Lenape) people, based on extensive fieldwork conducted during the early 20th century. This work details herbal remedies, ceremonial practices, and healing rituals, alongside the beliefs that imbue them with power—dream interpretation, spirit interaction, taboo observance, and symbolic acts. Tantaquidgeon emphasizes the integration of mental, physical, and spiritual healing, illustrating a holistic worldview in which illness arises from imbalance, not merely biology. The book also preserves chants, incantations, and cultural norms that might otherwise have vanished, making it an act of reclamation as well as scholarship. Sensitive, rigorous, and deeply respectful, her study remains a cornerstone of Indigenous studies and traditional medicine. It continues to serve Native communities, herbalists, anthropologists, and those seeking wisdom from a healing system rooted in reverence for the Earth and ancestral knowledge.