The development of social science terminology about ethnicity in the United States is traced from colonial times to the present, and conflict among ethnic groups is examined in relation to contemporary problems in the suburbs of New York. Early in U.S. history, immigrating ethnic groups were thought to contribute to the melting pot character of the country. At first, the melting pot concept emphasized conformity to the Anglocentric ways of the colonial settlers; later, it emphasized interaction among native and new groups as resulting in a unique combination with its own characteristics. Still another conceptualization of the melting pot was that ethnic groups continue to retain certain unique mannerisms while at the same time adapting somewhat to American social styles. This conception was the beginning of the theory of cultural pluralism, which by the early 1970s began to replace the melting pot theory. One phenomenon of ethnic immigration was the conflict which resulted between natives and immigrants. Because immigrants were willing to work hard for low wages, they took jobs away from some natives. This situation created bitterness and some violence on the part of natives. Ironically, as the immigrant groups were assimilated into American society, they themselves displayed enmity toward even newer ethnic immigrants who threatened their job security. Segregation and ethnocentrism among ethnic groups are evident today in the suburbs of New York. Mutual respect among ethnic groups will need to be developed there. (AV)