The prologue introduces the reader to Pan-American feminism: a movement that promoted women’s rights throughout the Americas over the first half of the twentieth century. It argues that inter-American feminism was at the vanguard of global feminism and international human rights. One of the movement’s signal contributions was its promotion of women’s rights treaties at Pan American and League of Nations conferences. The movement was also defined by its increasingly expansive definition of feminismo americano pioneered by Spanish-speaking Latin American activists, that included women’s political, civil, social, and economic rights; anti-imperialism; anti-fascism; and anti-racism. The movement culminated after the Second World War when, at the 1945 founding of the United Nations, a group of inter-American feminists pushed women’s rights and human rights into the UN Charter. The prologue introduces the six feminists at the heart of this activism: Paulina Luisi (Uruguay), Bertha Lutz (Brazil), Clara Gonzoz (Panama), Ofelia Dom쭧uez Navarro (Cuba), Doris Stevens (the United States), and Marta Vergara (Chile). Their friendships and their conflicts, over language, race, class, nation, empire, and different understandings of “women’s rights” and feminist strategy, were critical to the movement’s dynamics and its greatest accomplishments.