Dingell was born in Detroit, Michigan, the son of Marie Ciesielski Opalewska and Joseph A. Dzięglewicz, who were Polish immigrants from Bączal Górny.

He had also engaged in the construction of natural gas pipelines, was a wholesale dealer in beef and pork products and an organizer and trustee of Colorado Springs Labor College.

"[8] Reflecting the prevailing prejudices of the period, a memorable letter from Dingell to President Franklin D. Roosevelt on August 18, 1941, suggested that ten thousand Japanese-Hawaiian Americans be incarcerated in order to ensure "good behavior" from Japan.

[9] Following the Japanese attack on Pearl Harbor on December 7, 1941, Dingell "demanded that [Admiral Husband] Kimmel and [General Walter] Short be court-martialed.

A hallmark of their service has been a proposal for a national health insurance system, first introduced by John Sr. in 1933 and re-introduced since at every Congress by the father and then the son.