The advent of World War II was a major boost to the new company, from fifteen employees in 1938 the firm ended the war with over 5,000, a significant producer of aircraft parts.
Notably, McDonnell produced the XF-85 Goblin aircraft and Mercury and Gemini spacecraft.
McDonnell has also helped The HSUS celebrate National Farm Animals Awareness week, the Safe Cats campaign, Spay Day USA, and a number of important animal issues through his cartoons.
A resident of New Jersey, McDonnell also volunteered his talent and services to design a new animal-friendly license plate for the state.
He has been the recipient of two Genesis Awards and two commendations, which are bestowed annually by The HSUS Hollywood Office, and is on the Advisory Board of Hollywood Office as well.