The outgrowth of a conference intended to broaden the base of objective information about the Mexican American community, this collection of 13 papers examines the effects of immigration by people of Mexican origin on the economic, educational, social, political, and linguistic systems of the United States. Walker Connor's introduction puts the ethnic heterogeneity of the United States into a global perspective. J. Milton Yinger explains how immigrant groups move along the continuum of assimilation. Donald L. Horowitz explores the sources and control of ethnic conflict. John Stone compares recent migrant workers in western Europe with Mexican immigrants to the United States. Myron Weiner presents a detailed example from India to shed light on transborder conflict. Rosemarie Rogers focuses on economically motivated migration streams. Papers by Nathan Glazer, Rodolfo de la Garza, and Harry P. Pachon are devoted to the issue of Mexican American participation in U.S. politics. Papers by Shirley Brice Heath, Reynaldo. F. Macias, and Joshua Fishman address language policies. Topics include government policymaking with regard to language, language retention, bilingualism among Mexican Americans, language discrimination, and the quest for ethnic identification. A summary paper by Walker Connor emphasizes Mexican American heterogeneity. (JHZ)