Using the National Education Longitudinal Study of 1988 (NELS:88), we analyze how educational aspirations are formed and maintained from eighth to twelfth grades among a single cohort of youth. Guided by research in the status-attainment literature, which focuses on how aspirations are shaped, and the blocked-opportunities framework, which considers the structural obstacles that bound or level aspirations, we find that the relative shares of minority youth who have high educational aspirations are high from eighth to twelfth grades. However, ethnic groups differ in the extent to which high educational aspirations are maintained such that black and Hispanic youth have less stable aspirations. Our results suggest that family socioeconomic status (SES) not only contributes to ambitious aspirations in eighth grade but, more important, to the maintenance of high aspirations throughout the high school years. Because black and Hispanic students are less likely to maintain their high aspirations throughout high school, owing to their lower family SES background, we argue that their early aspirations are less concrete than those of white and especially Asian students. Focus-group discussions with adolescents support quantitative findings that, compared to whites and Asians, black and Hispanic youth are relatively uninformed about college, thus dampening their odds of reaching their educational goals.