Facing a continuing racial high school graduation gap, the state of Minnesota is emphasizing the importance of offering resources and opportunities to close this gap to prepare young adults to be adequately ready for success at the post-secondary level, that is, college and career. With this in mind, it is important to evaluate educational programs that offer resources such as targeted mentoring and a supportive learning environment and to estimate their impact on high school retention and graduation rates. We extend our analysis to a longitudinal study of 4-year-cohort graduation and retention rates across years using student-level administrative data from a school district in Central Minnesota on Access and Opportunity Program participants from 2008 to 2013. The combination of different cohorts allows us to disentangle cohort specific characteristics that could be correlated to rapid demographic changes that could impact students' success rates but are not related to the program itself. For instance, the entrance of new English learners in the system may bias educational outcome rates, underscoring the short-run effect of educational programs in the district. On the other hand, educational programs evolve across time and looking across the years would allow us to identify the intensity of the program and its evolution. We correct for selectivity and attrition issues based on observable characteristics and design a quasi-experimental analysis with information before and after the program started. We use as a control group most similar non-participant students. Furthermore, students who have been identified as eligible participants, but who elected not to participate, serve as another form of control. Our results show that compared to eligible non-participants, students of color participating in the program have higher odds to graduate from high school and, across cohorts, there is an increase in retention rates.