This episode marks the last time Lucy's children are referenced. In the first scene, she receives a letter from her son. In the last scene, she gets discharged from the Marines because she has two children.
In the first scene, when Lucy receives the letter from her son, she calls him Jimmy instead of Jerry because Lucille Ball confused the character's name with Jimmy Garrett, the actor who played Jerry. During filming, Ball had difficulty remembering this, so the error remained in the show.
Jim Nabors: as Gomer Pyle, his character from the Mayberryverse - The Andy Griffith Show (1960) and Gomer Pyle: USMC (1964).