Here are some background sources. Society of Illustrators: here for views by fellow illustrators. A detailed appreciation by illustration maven David Apatoff: here. James Gurney: here, presenting Gannam's depictions of mothers and children.
Another example of multiple illustrations with a common theme is bedroom scenes, the subject of today's post.
One reason for those bedroom scenes was that Gannam was contracted to illustrate advertisements for Pacific Mills' bedsheets. But he also painted some bedroom scenes under other circumstances.