This paper introduces research on the concepts of heritage language and bilingualism and explores the major perspectives and key positions concerning these issues. Within a recent decade a great deal of research has been carried out on linguistic minorities in the United States as well as around world. The number of scholarly works is compatible with the ever-increasing immigrant populations, the desire for diversity, and the rebirth of bilingual education in the United States. Since the late 1960’s, minority language communities have tried to maintain their languages in the spirit of the “new ethnicity” movement (Fishman, 1980, p. 167). Since the society in which a traditional language and English are maintained, bilingualism is almost always diglossic in multilingual society. One language, usually English, enjoys a higher linguistic status as a dominant, powerful communicative medium in many of these societies. English currently enjoys a global prestige that is unequalled and threatens the status of any other language in the United States as well as in the globalized world. Regardless of numerous endeavors among linguistic minority groups in recent years, the historic imbalance still exists between English and other heritage languages in the United States. Therefore, in this paper, it is necessary to define bilingualism and multilingualism. Second, the negative language planning traditions toward bilingualism in the United States is described. Then the positive rebirth of bilingualism and its effects on heritage language maintenance is discussed.