The purpose of this long term ethnographic study in a fourth grade bilingual classroom in a public school in Southern California was to explore how a teacher of linguistically and culturally diverse students, the majority of whom are of Mexican ancestry, established a community of learners. This teacher promoted bilingual and biliterate practices in Spanish and English, and addressed teaching and learning by placing common access to academic content at the center of classroom processes. The teacher-researcher team worked collaboratively for three years to make visible the ways in which the teacher established structures through literate practices across all areas of the curriculum. Data analysis helped identify the range of opportunities students had in this bilingual classrooms to become actively engaged in their own learning (Freire, 1983). The constructs of interactional spaces (Heras, 1993), and of positions and positionings (Davies, 1989;1993) were used to analyze microethnographic and sociolinguistic data on the ways participants constructed bilingual and biliterate practices. The study of micro-interactions was also interpreted in the broader context of bilingual education in the U.S. In particular, the ways in which participants´ interactions in the classroom reflected institutional and policy definitions at the school, the district, and the state level were identified. Data presented in this thesis were collected in the academic year of 1993-94 in the form of interviews, participant observations (videotapes and audiotapes), artifacts (drawings, writings, pictures), and school/district documents.