The previous answer is wonderful. I just wanted to add one aspect. The previous generations had specific hurdles and obstacles to overcome. WWI, the Great Depression, unemployment, social strife defined one generation. WWII defined the other. Yet Holden's generation is blessed with plenty and no viable threat. The Cold War and the invisible threat of communism do not provide a rite of passage for Holden's generation.
This isn't "The Greatest Generation". They have do deal with the plenty earned by previous generations.
The post-war atmosphere in America had two faces. On one side there was the economic boom, baby boom, prosperity and joy that the war was over. On the other side was the dark awareness that the bomb could at any moment decimate us, the same as we did to Japan, compliments of the USSR.
As Americans bought televisions, houses, cars and appliances in record numbers, there was an eerie feeling of instability underneath it all. Not economically, but a feeling that we could never really be safe again. Most families behaved in the conventional way and lived life ignoring the threats, except that the bomb shelter was a big item in the 1950s-1960s.
Holden Caulfield is dissatisfied with the upscale conventional lifestyle that he is forced to live.
He is like the returning soldiers who are consumed with the idea of death. In Holden's case it is the death of his brother, Allie. He believes that everyone around him is a phony. You could make a strong case, that 1950s society was based on pretending that everything was just fine, or phoniness, when at any moment we could be blown up by the A-Bomb courtesy of the USSR. This was the mindset in this period.
Holden exemplifies the gloomy, isolated, depressed nature of the period. While everyone around him is living, he stands still waiting to make a meaningful connection with someone who will understand him, and answer his questions.