John E. Dengler was born on March 18, 1918 to Samuel and Alice Dengler who lived in Elverson, Pennsylvania. His father was a well known cattle dealer, and served several terms as the Recorder of Deeds in Chester County. John was the youngest child of three children.
John attended local schools, as well as the University of Pennsylvania. He obtained employment with Dupont as an accountant, moving to Delaware.
John enlisted in the Army in May, 1941, and was commissioned as a 2nd Lieutenant at George Field, Illinois in August 1943. John received his “wings” as a B-24 Liberator Heavy Bomber co-pilot.