As we all know, A.A. partially grew out of the Oxford Group, a Christian movement which sometimes worked with alcoholics. But before the Oxford Group, there was the Emmanuel Movement based in Boston, Massachusetts. Two members in particular helped shape A.A.:

Ricard Peabody's The Common Sense of Drinking influenced the Big Book.Courtenay Baylor, who wrote Remaking A Man, treated Rowland Hazard in the early 1930's after Dr. Jung, and may have been the one to suggest he attend the Oxford Group, where he got the vital spiritual experience needed to be free of alcohol.Here is a brief history of this now-forgotten group (audio):

https://www.recoveryspeakers.com/the-emmanuel-movement-connection-to-aa-presented-by-jonathan-s-8-7-2020/