In this chapter, the authors describe nearly a decade of research examining postsecondary outcomes of students in the Chicago Public Schools conducted by the Consortium on Chicago School Research (CCSR). These analyses include both long-term trends in college going and findings on the dimensions of students' postsecondary transition experiences that shape those outcomes. The authors describe the evolution of research at CCSR, which emphasizes a specific type of partnership between researchers, district officials, and practitioners that builds the capacity of practitioners and district officials to think critically about big problems and utilize data to inform decision-making and evaluation. In addition to describing these findings, the authors discuss the development and operation of the Network for College Success, a research-based, integrated and intensive support for school improvement to principals, their instructional leadership teams, grade level teams, and counselors. The authors describe how NCS builds the capacity of school leaders to work together and to use data to improve practice in the postsecondary transition. Finally, the authors discuss ongoing challenges and new directions for ongoing and future research.