In this investigation, we replicated Skinner et al.'s study of the dynamics of engagement with a more diverse sample of Grades 6 and 7 students from a middle school with a large English learner (primarily Spanish-speaking) student population. We tested dimensions of the self-system model of motivational development in a specific academic domain (i.e., social studies). Some relationships found by Skinner and colleagues were supported, whereas others were not. Emotional engagement predicted changes in behavioral engagement and disaffection. The classroom context and students' self-perceptions predicted changes in engagement and disaffection. Students' self-perceptions also mediated the relation between teacher support and engagement and disaffection. None of these relations were moderated by language status.