This longitudinal study examined the education of language minority students in five school districts nationwide. Qualitative data included interviews, school visits, surveys, and source documents. Quantitative data included information from registration centers, language minority student databases, student information systems databases, testing databases, and other federal and state reporting databases. Overall, the districts have attempted to address the dimensions of the Prism Model of Language Acquisition for School (Thomas & Collier in Ovando & Collier, 1998) as they continue to improve programs for English language learners (ELLs). This model emphasizes four developmental processes that students experience through K-12 sociocultural, linguistic, cognitive, and academic processes. Findings demonstrate the importance of providing a socioculturally supportive school environment for language minority students that allows natural language, academic, and cognitive development to flourish in the native and second language. Findings note that each school context is different, and significant elements within each context can strongly influence students' academic achievement. Bilingually schooled students outperform monolingually schooled students in all subjects after 4-7 years of bilingual education. Short-term programs are not sufficient for ELLS with no English proficiency. The strongest predictor of L2 achievement is amount of formal L1 schooling. (Contains 24 references.) (SM)