Action takes place around the day of March 1st, 1962 (including the day before and the day after), which is the date the real American Airlines Flight 1 crashed on Jamaica Bay.
The song playing in the Japanese restaurant is commonly known as "Sukiyaki" in the U.S. The original, (Ue o muite aruko), was a number #1 hit in 1961. The song talks about putting on a happy demeanor even if one is faced with sadness or difficulty. In 1985, Kyu Sakamoto (the singer of the original song) died in a deadly single-aircraft accident.
During this episode it is revealed that Joan's birthday is February 24 1931 and she is 31 years old at the time of this episode.
The real American Airlines Flight 1 that crashed took the life of Louise Sara Lindner Eastman, the mother of Linda McCartney, famous photographer and wife of former Beatle Paul McCartney.
The episode reveals that Peggy is a Roman Catholic who attends church with her family. The fact that she does not partake in communion indicates that she has not been to confession in recent times and is thus not in a "state of grace" according to the Church. The service is conducted in Latin, in a nice historically accurate touch, as this is pre-Vatican II.