This article explores how a secondary ethnic studies course leveraged immigrant families’ literacies rooted in the Mexican spiritual ritual of Las Posadas for in-school literacy instruction and to engage in community-responsive grassroots processions as social protest. Using ethnographic and participatory design research, the authors—one a university researcher and the other an ethnic studies teacher—examine the literacy practices of a long-standing immigrant community–classroom partnership that unites day laborers, families, students, and teachers in the name of justice and refuge. Using photographs, interviews, students’ literacy artifacts, focus groups, and field notes, this study asks, (a) What do literacies look like in an ethnic studies course that designed learning around local community knowledge and sanctuary? (b) How do students respond to such curricular design? This study contributes ethnographic knowledge on school-based participatory research projects that build on the intergenerational literacies, sociopolitical awareness, and social movements of Latinx immigrant families.