In recent decades, researchers have analyzed professional military education (PME) organizations to understand the characteristics and transformation of the core of military culture, the officer corps. Several historical studies have demonstrated the potential of this approach, but they were limited by both theoretical and methodological hurdles. This paper presents a new historical-institutionalist framework for analyzing officership and PME, integrating computational social science methods for large-scale data collection and analysis to overcome limited access to military environments and the intensive manual labor required for data collection and analysis. Furthermore, in an era where direct demographic data are increasingly being removed from the public domain, our indirect estimation methods provide one of the few viable alternatives for tracking institutional change. This approach will be demonstrated using web-scraping and a quantitative text analysis of the entire repository of theses from an elite American military school.