While Sanger’s early focus was on increasing access to and information about birth control, one of her most loyal supporters, Katharine McCormick, consistently argued for the research and development of a new method of accessible, safe, reliable contraception controlled by women themselves, at a time when diaphragms, condoms, and withdrawal were common methods of birth control. Chapter 7 posits that McCormick’s feminism drove her to back development of the pill, correcting earlier historians who misunderstood her relationship with her husband. I also explain why Sanger and McCormick supported a prescription pill, which could be difficult for some women to obtain, while ostensibly trying to expand access to birth control. The chapter traces the way McCormick’s scientific interest in endocrinology, which developed from her intervention in her mentally ill husband’s medical care, and her feminist philosophy came together in her funding of the development of the birth control pill. At a time when Planned Parenthood was uninterested in research or concerned with developing a new contraceptive method that women could control, McCormick insisted that a pill was both possible and necessary, and she paid for its development by Gregory Pincus and John Rock. She then worked to ensure that women had access to the pill through its distribution at hospital clinics. McCormick single-handedly financed the expansion of reproductive rights for women through the development of the pill.