When Robert Johnson discovered Charles Fort is not known.  But, recently I had a chance to go through some of the Eric Frank Russell papers, and a letter to him from Tiffany Thayer makes clear that the San Francisco branch of the Fortean Society was in full swing by the late 1940s.  He wrote (in 18 FS, which, according to Thayer's idiosyncratic marking of time is 1949), "Our San Francisco--Chapter Two--is going great guns.  Meetings that last all night and so on."

Johnson, of course, was in San Francisco at the time, and should have been familiar with some of those who had an interest in matters Fortean.  He was not, however, "a 'joiner,' by nature," he told Damon Knight.  "And have always stubborny refused to hold any office in the very few organizations to which I have belonged.  In my judgement, it takes up too much time, for a writer; and distracts too much from his own work."

But, he must have joined relatively soon after its founding, because he was there in 1951 when Thayer excommunicated Chapter Two.

As Johnson has it, his interest in Fort was two-fold.  First, Fort provided a great number of story ideas.  In 1951, he told the Berkeley, California, Elves,' Gnomes' and Little Men's Science-Fiction, Chowder and Marching Society, "It was recently proposed to form a club that would be called, 'Writers Who Have Stolen lots from Charles Fort.'  The idea was dropped, however, when it was realized that such a group would include virtually every writer in the imaginative field, including many now deceased."

Johnson was also interested in damn facts--which, as he tells it, was the cause of Chapter Two's eviction from the Fortean Society sometime in 1950 or 1951.  The group dutifully collected reports of anamolous events and even gathered ice that fell on Oakland in the middle of summer.  These reports they passed on to Thayer, who complained that his Society was more interested in political things ("other rebellions") than traditional damned facts.  Apparently upset over the direction of the San Francisco chapter, Thayer withdrew their charter; the Bay Area Forteans resigned en masse and reconstituted themselves as Chapter Two.

Su upset over Thayer's direction was Johnson, that he never bought any issues of Doubt and publically complained to the Berkeley group.  That complaint was later  published in the groups fanzine Rhodomagnetic Digest, then reprinted in If and Anubius--indicating the continued interest in Fort among science ficiton and fantasy enthusiasts.

According to Johnson's later recollections, Chapter Two continued to meet until the death of Kenneth MacNichol and Polly Lamb.  He dates this as 1957 for MacNichol and 1958 for Lamb--giving Chapter Two a lifespan of eight or nine years--but his memory, as should be obvious by now, cannot always be trusted, and the official records on this matter are still unclear.  Further research is necessary.  Which is perfect, because Kenneth MacNichol is the next subject.