In "Goin' Home: Part 1", Sonny mentions to Will that when they get to Sonny's home town, he is going to visit his son's grave, and does so with his former daughter-in-law, Julie.
It is learned Sonny had a son that went to Vietnam and was killed in action. Even though his ex-wife was shown at length in Goin' Home: Part 1 (1974) and Goin' Home: Part 2 (1974), no mention was made of them having a child. Additionally, Good for Laughs (1974) featured a Vietnam war buddy of Will's and again no mention was made of Sonny's son.
This marks the first appearance of Art Metrano and Rosey Griey as Moose and Benjy, respectively.