There have been some great responses as to the similarities of the Catcher Covers:
1. All the covers have red- this could be seen as a symbolism for communism. And considering the events that were happening in 1949-1950, that is a great assessment.
2. The horse carousel image is indicative of the loss and acceptance of childhood
3. The other thing that I feel is the strongest correlation between all the covers is the anonymity in all the covers. All the covers are very simple, with no information on them giving you any indication as to the story within. If you look at the fronts and backs of the books, most are the same.