In this dissertation I present the main findings of a multiple case study using an ethnographic approach to explore high school teachers and students' understandings and practices of citizenship and citizenship education in a public, a private-subsidized, and a private independent school in Santiago, Chile. The study showed how citizenship education was understood very differently in each school, ranging from a patriotic to a social-justice oriented approach, which was reflected in the curriculum, extracurricular activities, civic ceremonies, expectations of students, and in the way student government functioned and how students perceived their role in it, among other aspects of school life. These differences worked to perpetuate social reproduction and contributed to the civic opportunity gap, but a dimension of resistance complicated this, showing a political side to what is commonly seen as civic disengagement in poor students. It also showed how students' identity as citizens was mediated by the discourses of abajismo and arribismo fostered at the schools, promoting in students a misrecognition of their social class, that works against a critical and transformative approach to inequality. Regardless of the type of school and citizenship education approach, all schools experienced pressure from the accountability context, limiting time for citizenship education to favor a focus on standardized tests; and showed a tendency to isolate students from their community, and to see them as not-yet-citizens. This meant schools acted mostly as spaces of socialization, concerned with forming students that adapted to the system, rather than promote their agency. [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.]