For socioeconomically disadvantaged children, a positive experience in kindergarten may play a particularly important role in fostering the behavioral adjustment and learning engagement necessary for school success. Prior research has identified supportive student--teacher relationships and classroom emotional support as two features of the classroom context that can promote student adjustment; however, very few studies have examined these two aspects of the classroom context simultaneously. Given their modest intercorrelations, these dimensions of classroom context may have both unique and shared associations with child progress. This study followed the cases of 164 children as they transitioned from Head Start into elementary school, and regressions revealed significant unique associations between each type of kindergarten support and children's aggressive behaviors, social withdrawal, learning engagement, and emergent literacy skills in first grade, controlling for their prekindergarten adjustment. In addition, learning engagement significantly mediated the association between a supportive relationship with the kindergarten teacher and first-grade literacy skills.