Tomorrow Is Forever (1946)

Elizabeth and John say goodbye as John leaves to go to war. When World War I ends, Elizabeth receives a telegram that John has been killed in action. She finds comfort in Larry and they marry. John returns 20 years later, disfigured, with a new identity--Erik--and an adopted daughter, Margaret. John/Erik and Elizabeth accidentally meet and he learns that he has a son, Drew. John must then decide whether or not to reveal his true identity.