The relation between Margaret Sanger's character and the nature of the birth control movement she led in the U.S. is explored from 1912, when her pioneering work began, until 1945, when, simultaneously, the U.S. government accepted the idea of birth control and Mrs. Sanger retired from leadership of the movement. The book tries to illuminate, through Mrs. Sanger's life, an aspect of American society of that period, the context in which Mrs. Sanger worked, and the attitudinal and institutional responses she evoked. The focus is on the public career of Margaret Sanger, not her private life. A thorough bibliographical essay and selected bibliography are included at the end.