The interactions of white Mennonites with African Americans between 1940 and 1971 show how Christianity helps maintains racial distance in the U.S. Through their everyday involvement in evangelism, rural visitation programs, voluntary service projects, church proclamations, and congregational integration, white Mennonites tried to reduce the social gap between black and white by changing group boundaries. However, historical and sociological evidence from Germanic-Swiss and Russian Mennonite communities in the states of Indiana, Kansas, Mississippi, New York, Pennsylvania, and Virginia reveals the failure of one-sided efforts to include those defined by society as racially unclean. Concepts of religious purity coupled with racial ideas of whiteness prevented white Mennonites from entering into full fellowship with the African Americans targeted by their mission initiatives. The synergy of Mennonite belief in service, separation, and symbol drew attention away from internal patterns of control over African-American converts and service recipients. Ironically, the very ideal of purity that inspired Mennonites to challenge racial injustice instead marginalized African Americans. This interdisciplinary study offers cautious hope for more careful employment of the Christian values of purity and service in the face of continuing racial injustice and the racial distance it engenders.