During World War 2 he piloted B-24 bombers on raids over Germany and northwestern Europe. He can be seen in the photo above standing just to the right of the English boy.
Saxon's Wikipedia entry is here, and information regarding his military service is here.
His family background appears to have been upper-middle class, and those people and upper-class folks were his usual cartoon subjects.
Below are samples of his sketchy, slightly spare, but effective and appropriate (for his subject matter) style. Unfortunately for Saxon and us, a change in New Yorker editorship essentially ended his career there. However, he also derived income illustrating advertising material.
There is a common element in each of the cartoons below. Do you notice it?
What appears in each cartoon is at least one painting. In some cases, paintings are the subject. In others, they are part of the setting. I think Saxon deliberately chose the type of setting painting as one of his environmental means to define the people acting out the cartoon's punchline.