After Pearl Harbor, Jack McClellan volunteered for the US Army Air Corps. He served four years in England, France, and Germany, and then used the GI Bill to earn a master's and doctorate degrees in education at the University of Southern California, where he was an adjunct professor. He was a teacher, supervisor, and assistant superintendent in the Los Angeles Unified School District. He authored numerous teaching and educational materials for such publishers as IBM and Houghton Mifflin. He enjoys traveling and gardening and is an avid stamp collector.