An 8-year ethnographic study in two rural Iowa towns examined the incorporation of recently arrived Mexicans and Mexican Americans into the social, economic, and political life of the community. Relocating to work in a nearby food processing plant, the newcomers altered the ethnic composition of this formerly homogeneous area. Data were gathered through in-depth interviews, informal conversations, observation of community events, and review of government documents and local newspapers. Conceptual frames for the study include modes of incorporation, racial formation and racialization, and social regulation. The experiences of Mexican and Mexican American newcomers demonstrate how local social regulatory activities circumscribe the ways in which these new residents can make claims as permanent members of the community. These social regulatory activities construct the racialized, gendered, and class-specific grounds on which Mexican Americans can earn a living wage, access social services and education, and gain a political voice. Various experiences of the newcomers are described, including recruitment to the food processing plant, poor working conditions, disadvantages arising from limited English proficiency, local resistance to providing English as a second language classes or offering Spanish in school, lack of proficient translators in the school and community, harassment by the police and the Immigration and Naturalization Service, lack of affordable housing, harassment and discrimination during use of health and social services, biased attitudes of educators, and community fears about Hispanic youth. (Contains 116 references.) (SV)