This dissertation challenges the prevailing notion that everyday, working-class African Americans and Euro-American Catholics in urban areas did not participate in interracial activities until after the modern civil rights movement and the Second Vatican Council of the 1960s. Despite racial segregation entrenched in the 1910s and 1920s within the boundaries of three black Catholic parishes on Chicago's South Side, African Americans interacted with whites by participating in inter-neighborhood activities during the Great Depression and World War II years. Under the pastoral leadership of Bishop Bernard J. Sheil, the Catholic Youth Organization (CYO) sponsored educational, recreational, and social programs for thousands of children and young adults in Chicago from 1930 to 1954. This multicultural and ecumenical association of neighborhood youth programs included blacks and whites, as well as Protestants and Jews from throughout the city. Collaborating with federal New Deal and Chicago Park District programs, CYO public-private partnerships provided interracial opportunities for urban youth in the spirit of civic and pluralistic values - until eclipsed by American society's Cold War emphasis on nuclear families, suburbs, and anti-Communism. Oral interviews, archival materials, and journalistic accounts present compelling evidence of interracial engagement within urban, working-class settings in the 193Os and 1940s. An examination of CYO successes and failures, this study offers historical lessons for today's faith-based programs committed to ecumenical and interracial opportunities for youth.