His father's death, when John was still a boy, influenced his decision to leave high school early to help support the family — his mother, brother William, and sister Genevieve.
DePol worked as a securities runner on Wall Street and expected that there, beyond this beginning at picking up and delivering certificates of stocks and bonds bought and sold, lay an opportunity to make his fortune.
He was employed but four weeks when the stock market crashed during the latter half of October 1929, and only then discovered his fortune merely in holding on to a job at a time when many were losing theirs in the Depression.
In the evening DePol attended night school, where he learned typing and shorthand, which were to prove useful for his later stenographic and secretarial positions in civilian and military life - the first of these through a company promotion into a special investments department.
Even these early works, done with almost no professional training, show DePol's sense of design, use of light and shadow, and his abiding interest in the lives of ordinary people.