The purpose of this study is to analyze the reasons behind governmental decisions leading to the "English-only" instruction policy in the public schools and the recent softening of this policy by various state and local governments. The author's thesis is that such policies have considered neither the advantages which the child may have if he learns in his native tongue nor the willingness of the non-English speaking groups to learn English. He finds, rather, that official acceptance or rejection of bilingualism in American schools has depended on whether the group involved has been considered politically and socially acceptable, and that the decisions to impose English as the sole language of instruction have reflected the popular attitudes towards that particular ethnic group and the degree of hostility evidenced toward that group's natural development. The author analyzes the experience of five groups: German-Americans, Mexican-Americans, Japanese-Americans, American Indians, and Puerto Ricans in Puerto Rico. He shows the different behavior manifested by the government at various times towards these groups and how the requirement that English be the exclusive school language was imposed or withdrawn as government policy changed. Finally he examines the Bilingual Education Act and what it suggests as a government policy for the future. (FWB)