Sara Josephine Baker (1873-1945) was born in Poughkeepsie, New York, and attended the Woman's Medical College of the New York Infirmary. As the first director of New York's Bureau of Child Hygiene from 1908 to 1923, Baker's work with poor mothers and children in the immigrant communities of New York City dramatically reduced maternal and child mortality and became a model for cities across the country. On two occasions she helped to track down Mary Mallon, the cook who came to be known as Typhoid Mary. Baker wrote fifty journal articles and more than two hundred pieces for the popular press about preventive medicine, as well as six books: Healthy Babies, Healthy Mothers, Healthy Children (all 1920), The Growing Child (1923), Child Hygiene (1925), and her autobiography, Fighting for Life (1939). In the 1930s Baker, along with her partner of many years, the novelist Ida Wylie, and their friend Dr. Louise Pearce, moved to a two-hundred-year-old farm in New Jersey, where she lived until her death.

Helen Epstein is a writer specializing in public health and an adjunct professor at Bard College. She has advised numerous organizations, including the United States Agency for International Development, the World Bank, Human Rights Watch, and UNICEF. She is the author of The Invisible Cure: Why We Are Losing the Fight Against AIDS in Africa and has contributed articles to many publications, including The New York Review of Books and The New York Times Magazine.