A comment by "dearieme" over at Chicago Boyz put me in mind of a conversation that used to be common, but I, at least, don't run into anymore. The America of my youth was more local in its orientation. While the principle of being an American was more universally-held from sea to shining sea, we were still quite provincial. Americans were regional, or even narrower. As a consequence, the phrase "rich people" drew images of North Elm St, North River Rd for us, and only secondarily Rockerfellers, Newport RI cottages, or those people in Southern California. My mother's second marriage brought us into the fringes of that. My stepfather was wealthy and well-placed enough, but he had come from North Haven, CT, and his sons went to Tilton, not St Paul's. For her part, my mother brought in some older local aristocracy, as my grandfather was the first CPA in NH and had grown quietly respectable in the inner circle by the time I was aware of such things. (My grandmother, a social climber, resented that he did not exploit this socially or move her to the North End.) Again, the fringes of the local aristocracy.
High school graduates were discouraged from going to college out-of-state, and going out of New England was met with blank stares. My decision to go to William and Mary was sometimes met with blank stares - people didn't know where it was, and were surprised that one of the smart boys would go to such an obscure school. In my time at W&M there were only two of us from NH - and I knew her, of course, confirming the stereotype that everyone in VA had of NH. That lack of recognition was still true a few years later when I returned. My era was right at the inflection point of this. When my younger brother left college to go to California in 1977 it was no longer considered that unusual.
I suspect there was some regional variation in when this crossover occurred. I had the impression that the schoolmates of the kids from New Haven to DC were more widely dispersed. New Englanders had had their big move in the early 1600's or 1760's (a bunch then went to the Midwest in the mid-1800's), other Europeans came in later and stayed put as well, and that was about it.
The awareness of this in culture was a generation behind when it had actually started occurring. People were certainly heading to California or Florida well before 1971, but they hadn't yet become rich or famous or important enough to be national. When that new fashionable phenomenon McDonald's first came to South Willow St in 1965, no one remarked that the McDonald brothers were originally from Manchester. That only dawned on us much later. The awareness grew that Americans were starting to move all over after WWII, and everyone now understands this migration, especially to Southern California, as one of the great matters of the 20th C. But that idea was not fully formed by 1970. People were moving...everyone had a friend or relative out there...but each decision was seen as idiosyncratic. The reasons were still being assembled in our heads.
Interstate highways. More cars. Pacific Theater vets who had disembarked on the West Coast and loved it. Kids who wanted to get into the movies somehow. People who disliked their towns or their families and wanted out. People who wanted nicer weather. We all know those now, and I imagine the people in the receiving cities - Houston, LA, Phoenix, SF - figured out the patterns before those back home did, comparing stories.
Yet culture nationalised even for those who stayed home. Television and network news became national, or NYC/DC/LA/Everywhere Else national anyway. Local radio has always hung on, because of the auto. Local TV, not so much. Local newspapers, dying. One of my favorite obscurer theories is that teenagers having spending money for the first time in history created a national generational culture, and we Boomers have been annoying the hell out of everyone else since. Local aristocracies - barely recognised now. Those of us over 60 can still see names on local business or charitable boards and think "Old Manchester," but it's not so tight now. Rich people move in, move out. They are more part of a national upper class than a local one now.