A well-known American academic and cofounder of Boston's first settlement house, Emily Greene Balch was an important Progressive Era reformer and advocate for world peace. Balch served as a professor of economics and sociology at Wellesley College for twenty years until her opposition to World War I resulted with the board of trustees to refusing to renew her contract. Afterwards, Balch continued to emphasize the importance of international institutions for preventing and reconciling conflicts. She was awarded a Nobel Peace Prize in 1946 for her efforts in cofounding and leading the Women's International League for Peace and Freedom (WILPF). In tracing Balch's work at Wellesley, for the WILPF, and for other peace movements, Kristen E. Gwinn draws on a rich collection of primary sources such as letters, lectures, a draft of Balch's autobiography, and proceedings of the WILPF and other organizations in which Balch held leadership roles. Gwinn illuminates Balch's ideas on negotiated peace, internationalism, global citizenship, and diversity while providing pointed insight into her multifaceted career, philosophy, and temperament. Detailing Balch's academic research on Slavic immigration and her arguments for greater cultural and monetary cohesion in Europe, Gwinn shows how Balch's scholarship and teaching reflected her philosophical development. This first scholarly biography of Balch helps contextualize her activism while taking into consideration changes in American attitudes toward war and female intellectuals in the early twentieth century.