There are fewer evidence-based social and emotional learning programs for middle school students compared to younger grades. This randomized controlled trial tests the effectiveness of Facing History and Ourselves (hereafter, Facing History) with a sample of 694 (Facing History n = 437; Comparison n = 257) students from a low-resourced school district. Youth self-identified as female (59%), Black/African American (61%), Hispanic/Latinx (18%), White (2%), and multi-racial or some other race/ethnicity (19%). Intervention students perceived their classrooms as more caring and democratic than students in the comparison group. They reported higher levels of empathy, prosocial behavior, and stronger participatory citizenship beliefs. This study expands the evidence-based of effective SEL programs available to schools.