While the field(s) of management theory and the history of modern ideas in management, business education and organizations have many different intellectual roots, the Carnegie Mellon Behavioral trio (James March, Herbert Simon and Richard Cyert) who founded the behavioral perspective on organizations stand out not just for their collective contribution to founding the field of organizational behavior as we know it today, but also for their subsequent individual contributions to the field. Organizations and Behavioral Theory of the Firm set the stage for several subsequent developments in organization and management theory including research on learning, strategic management, organizational economics and organizational routines (Gibbons, 2003; Pierce, Boerner & Teece, 2002; Williamson, 2002, 2004; Augier & Teece, 2005, 2009). In addition to providing some background on the Carnegie work, this paper traces the genealogy and development of some of the work of the founding fathers, and making the points that (1) while the work of Herbert Simon crossed disciplinary boundaries, he saw himself as doing only one thing, working in understanding limited rationality in decision making and (2) the work of James March shaped the field in  co-evolutionary way