This chapter explores how early-twentieth-century Pan-American feminism shaped international human rights and influenced the 1945 UN Charter and 1948 Universal Declaration of Human Rights. In the 1920s, inter-American feminists created the first inter-governmental organization to promote women’s rights in the world—the Inter-American Commission of Women—and innovated an Equal Rights Treaty, a proto-human rights instrument. In the 1930s and 40s, a broad Popular-Front Pan-American feminist movement connected women’s equal rights treaties and demands with social and economic justice, as well as with anti-fascism, anti-imperialism, and anti-racism. This movement helped drive a bourgeoning language of international human rights as “rights for all regardless of sex, race, class, or religion.” Popular-Front Pan-American feminism was responsible for the presence of Latin American feminists, including Bertha Lutz (Brazil), Minerva Bernardino (the Dominican Republic), Amalia de Castillo Ledón (Mexico), and Isabel Pinto de Vidal (Uruguay) at the meeting that founded the United Nations Charter in 1945, and compelled their work there. This Latin American bloc was responsible for pushing women’s and human rights into the Charter and for proposing what became the UN Commission on the Status of Women. Inter-American feminists also helped shape the 1948 Universal Declaration of Human Rights.