A graduate of Tulane University with a degree in architecture, Callender served on the Mexican border with the National Guard in 1916. In June of 1917, he joined the Royal Flying Corps in Canada. Assigned to 32 Squadron in May of 1918, he was shot down in June but was uninjured.

On October 30, 1918, in the heaviest air fighting of the war, Callender's S.E.5a was shot down over Ghislain by members of Jasta 2. Falling behind his own lines, he soon died from a fatal chest wound. Callender's descendants published a collection of his letters and photographs entitled "War in an Open Cockpit."