General chemistry is a gateway course that impacts the STEM trajectory of tens of thousands of students each year, and its role in the introductory curriculum as well as its pedagogical design are the center of an ongoing debate. To investigate the role of general chemistry in the curriculum, we report the results of a posthoc analysis of 10 years of archived student data (ca. 12,000 students) aimed at discovering whether taking college-level general chemistry has an impact on student performance in and progression to subsequent chemistry courses. We introduce regression discontinuity; a quasi-experimental method that originated in educational psychology and can be used to estimate causal impacts of educational treatment when ex ante randomization is not feasible. Using regression discontinuity, we estimated a positive impact of prior general chemistry coursework of about one-fourth of a letter grade in two subsequent courses, Organic Chemistry I and a physical general chemistry course for nonmajors. We also found that taking general chemistry had no impact on the likelihood that students will progress to the final course in the nonmajors sequence.