Per the foreword to The Case of the Smoking Chimney, Gramps Wiggins is based on someone that Erle Stanley Gardner met: "More frequently than they realise, authors are inspired by outstanding individuals whom they meet.
Two years ago in New Orleans I met a litle old chap who has as much bounce as a rubber ball, whose eyes sparkle with enthusiasm, whose white hair shaggles down around his shoulders.
Whitesell was a photographer who didn't care about money and was frequently too busy to think about eating, as he tried to crowd all the activities he wanted to do into the day.
Gardner said "Whitesell and Gramp Wiggins are, of course, two distinct entities, although they have numerous points in common.
All I know is that after a winter in New Orleans during which I became well acquainted with Whitesell, Gramp Wiggins walked into my consciousness one day and demanded to be set down on paper.