The San Diego Unified School District (SDUSD) supports teaching and learning in California's second-largest school district, educating students from preschool to high school each day. Nearly three quarters of SDUSD students are students of color, including 47% who are Latino/a and 9% who are African American. Almost 60% of students are economically disadvantaged, and 24% are English learners. Despite the wide achievement gaps across the state between students from different racial and socioeconomic backgrounds, SDUSD has excelled at supporting the learning of all students. SDUSD is one of seven districts studied by researchers at the Learning Policy Institute in a mixed-methods study that sought to learn from positive outlier districts in which African American, Latino/a, and White students all did better than predicted on California's math and English language arts tests from 2015 through 2017, after accounting for differences in socioeconomic status. This in-depth case study complements the research series by describing the practices and policies within SDUSD that have promoted student learning, especially among students of color, in the context of the Common Core State Standards (CCSS) and the deeper learning they seek to foster. Through an analysis of interview, documentary, and observational evidence, this report describes how SDUSD has combined a commitment to instructional improvement and a system of holistic student supports to bolster achievement for all students. Additionally, it identifies five key factors that have enabled student success in SDUSD.