Hermann Weinraub is the biological father of Abraham Morgan. Abe found out who his parents were and his true last name in the episode "Hitler on the Half-Shell."


Hermann married Rita Weinraub and later had a son named Abraham who was born around 1945. It is assumed that Hermann and Rita were Jewish and were placed in a concentration camp around the time Abe was born. When Henry Morgan found Abe, he decided to adopt him and so Abe never knew his parents. They most likely were killed at the camp or just never found their son.