|Abstract||This dissertation argues that during World War II, an ecumenical group of Protestant missionaries working through the Protestant Commission for Japanese Service sought to influence federal policy toward incarcerated Japanese Americans and to ameliorate the conditions faced by the 110,000 Japanese Americans in federal incarceration camps. Influenced by a commitment to Christian internationalism, the missionaries believed their vocational calling was to reform through Christian practice the racist and exclusive policies that shaped government and public attitudes toward Japanese Americans. The views of the missionaries had changed through their years of service in Japan. While most accepted versions of Christian imperialism in the first decades of the twentieth century, after World War I they moved increasingly toward a vision of Christian internationalism that created kinship among Christians across racial, linguistic, and political borders.^This belief prodded them to create bridges between Americans and Japanese as the two nations edged toward war. After Pearl Harbor, the missionaries tried to counter the increasing call to remove and incarcerate all citizen and resident Japanese Americans living on the West Coast. Failing in that effort, they became the official mediators among federal authorities, Protestant denominations, and Japanese Americans in the camps. Their efforts to protect the religious freedom of Japanese Americans occasionally blurred the lines between church and state. While Commission members visited the camps regularly and carried on public relations campaigns across the country, other missionaries sought employment as religious workers or War Relocation Authority employees in the camps. As they built relationships with Japanese Americans and called for the protection of minority civil liberties, the missionaries also looked forward to returning to their posts in Japan after the war.^^The experience working with and on behalf of Japanese Americans during World War II pushed many of the missionaries to embrace postures of humility, repentance, and partnership with Japanese Christians on their return to Japan postwar.