As Louise Brown—the first baby conceived by in vitro fertilization—celebrates her 30th birthday, Margaret Marsh and Wanda Ronner tell the fascinating story of the man who first showed that human in vitro fertilization was possible. John Rock spent his career studying human reproduction. The first researcher to fertilize a human egg in vitro in the 1940s, he became the nation’s leading figure in the treatment of infertility, his clinic serving rich and poor alike. In the 1950s he joined forces with Gregory Pincus to develop oral contraceptives and in the 1960s enjoyed international celebrity for his promotion of the pill and his campaign to persuade the Catholic Church to accept it. Rock became a more controversial figure by the 1970s, as conservative Christians argued that his embryo studies were immoral and feminist activists contended that he had taken advantage of the clinic patients who had participated in these studies as research subjects. Marsh and Ronner’s nuanced account sheds light on the man behind the brilliant career. They tell the story of a directionless young man, a saloon keeper’s son, who began his working life as a timekeeper on a Guatemalan banana plantation and later became one of the most recognized figures of the twentieth century. They portray his medical practice from the perspective of his patients, who ranged from the wives of laborers to Hollywood film stars. The first scholars to have access to Rock’s personal papers, Marsh and Ronner offer a compelling look at a man whose work defined the reproductive revolution, with its dual developments in contraception and technologically assisted conception.