The purpose of this study was to examine the degree to which academic achievement in U.S. schools could be explained by several indicators of belongingness (i.e., close teacher-student relationships, peer acceptance, school liking, low levels of loneliness in school and positive perceptions of peers) and school engagement. For this study, data were collected from a sample of 280 third and fifth grade Latino and Anglo children (152 boys; 128 girls) in the fall of the academic year with follow up academic achievement data gathered approximately 5 months later. A multi-group structure equation modeling approach was used to test direct and mediating relationships among the variables and to determine if the model was moderated by ethnicity. Consistent with previous research, Latino children had lower achievement scores than their Anglo counterparts; however, no other ethnic differences were detected in mean levels of the study variable. Moreover, correlational analyses revealed that, while the proposed indicators of belongingness correlated as expected for Anglo children, no discernible pattern of association was found for Latino children. Similarly, while the proposed belongingness indicators all correlated with measures of school engagement (i.e., compliance, enthusiasm, and independence) and academic achievement for Anglo children, only close teacher-child relationships and positive perceptions of peers were significantly correlated for Latino students. Because of these ethnic differences, the initial proposed model was modified to only include teacher-student closes and positive peer perceptions as predictors of engagement and academic achievement. Tests of the mediation model revealed that for both groups of students, school engagement mediated the path from close teacher-student relationships and concurrent and later academic achievement. However, the links from positive peer perceptions to Time 1 and Time 2 academic achievement via school engagement was only significant for Anglo children. Overall, the findings highlight the importance of the teacher-student relationship for Latino children; that is, encouraging and caring relationships established with teachers may be especially critical for Latino children's motivation and achievement success in U.S. schools than for their Anglo peers. Group differences and implications of these findings are discussed as well as the strengths and limitations of the study. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]