It is true that the 1950s in America prompts more nostalgia that most any other time period we can uniquely define. I think the era was defined by conflict for the same reason that it was nostalgic. Quite simply, things seemed to be getting better. For example, the civil rights movement was making incredible moves for the better.
People get nostalgic about every decade, but the 50s are the one that people seem to feel was actually an objectively better time (for some demographics, like white men, especially). A big reason was that, at that time, with that level of population and resources, capitalism seemed to be working. If you worked hard, you could really attain the American dream. Today, there is an overwhelming sense of futility in regard to getting ahead, but the single breadwinner ideal was real and attainable for middle-class families back then.