Billie Alban and I created the OD History Chart sometime in the 1990s when we found that people coming to our Large Group Methods workshops didn’t understand how these methods had developed and where they came from or how they were a part of Organization Development. Billie’s granddaughter did the illustrations. About 2008, Dick Axelrod and I updated it in order to talk about the history of OD in the Columbia University/Teachers College certificate program called Principles and Practice of OD. We even made a big wall chart of it. We found that it’s visual characteristics helped people understand the several streams of thinking and research that created OD. Recently Dick and I have made a new diagram about the history of OD that puts the chart in context. I will describe that thinking first and then explain the chart. Everyone has a story about how it all began. Here is mine.