As Anthony Comstock was to the late nineteenth century, Margaret Sanger would be to the early twentieth. They were, in a curious way, ideological mirror images of each other. They shared the same prophetic style, the same absolute certainty, and the same relentless will, while standing at opposite ends of the birth control question. 1 Where Comstock built and successfully enforced a legal empire that equated contraception with obscenity, Sanger transformed birth control from a perverse act into—for many—a righteous practice. Where Comstock mobilized a united American Evangelical Empire behind his enterprise and also enjoyed the tacit support of Roman Catholics, Sanger used latent anti-Catholicism and a form of “soft” eugenics to swing the postmillennial Social Gospel Protestants behind her cause.