An extensive theoretical and qualitative literature stresses the promise of instructional practices and content aligned with minority students’ experiences. Ethnic studies courses provide an example of such “culturally relevant pedagogy” (CRP). Dee & Penner (2017) provided the first credibly causal evidence of the effects of ethnic studies on academic outcomes at the end of ninth grade in San Francisco Unified School District (SFUSD). Assignment to this course increased ninth-grade attendance by 21 percentage points, GPA by 1.4 grade points, and credits earned by 23. Current work extends this research by examining the scale-up of ethnic studies in SFUSD and spread of similar courses to districts around the country.