The purpose of this quantitative causal-comparative study was to examine if, or to what extent, there is variability in a student's probability of graduating based on an intervention of making a first-year seminar (FYS) course mandatory in 2006 compared to before 2006 when FYS courses were optional when controlling for race/ethnicity, gender, and type of student (traditional versus non-traditional) at a university in the Northeastern United States. Prior research indicated a significant need for a long-term, comprehensive analysis of the influence of student success programs, supplemental instruction courses, and FYS courses on student retention, especially for minorities, non-traditional students, and gender gaps in persistence to completion. The theoretical framework and design of this study are based on a synthesis of Mezirow's theory of transformative learning and Tinto's theories of student persistence, institutional action, and societal theories of departure. The study used binomial logistic regression analysis to analyze data consisting of 35,102 first-year freshmen graduation rates from a four-year university in the northeastern region of the United States to compare graduation rates before and after the intervention for the years 1996-2015. Research results revealed that the odds of graduating increased for all three control variables. Non-traditional students showed the most improvement in graduation rates. The results of the study may support administrative decision makers' long-term investment in student performance and support measures. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]