This document discusses the history and evolution of organizational development (OD). It describes how OD emerged from laboratory training in the 1940s, survey research and feedback in the 1950s, and action research. Major contributors to early OD approaches included Kurt Lewin, Douglas McGregor, Rensis Likert, and John Collier. Over time, OD expanded to incorporate additional influences like quality of work life programs and approaches for managing strategic change. The document outlines the key stems and phases in the development of OD and profiles many important thinkers who advanced the field.