[1] Campbell, Parker, and their collaborator, Robert Carson, earned an Academy Award nomination for Best Adapted Screenplay for 1937's A Star Is Born.

He and Parker also wrote additional dialogue for The Little Foxes when Lillian Hellman was called away to work on another project.

He was commissioned a captain, and served in Army Intelligence in Europe for the duration of World War II.

While Parker insisted that he would never have intentionally killed himself, and reported his death as "accidental", he had been drinking all day; capsules of the barbiturate Seconal were found around his bed, and a plastic bag was draped over his neck and shoulders.

The coroner's report listed the cause of death as "acute barbiturate poisoning due to an ingestion of overdose".