@glitterbag,
I'm the son of Irish Immigrants who fled Ireland as adolescents in the aftermath of the revolution and civil war ( soon after De Valera & co assassinated a Michael Collins). We lived in Detroit where ( I suspect much like New York at that time) the city was divided into ethnic enclaves populated by Italians, Irish,Poles, Czechs & Slovaks Greeks, Danes, German and Ashkenazi Jews ( distinct groups), Syrians, as well as Blacks, and what we called Hillbillies, who migrated there during WWII. Each had fairly well defined neighborhoods with well known boundaries, and there was a general level of friction - some friendly, some not - among and between them. If you were asked "What are you", and answered "American" you had to be tough. Such group identities were the norm. Amidst all that, it was hard to single out one particular struggle from the others. One from any group had to compete and get smart early. Suburbs like Grosse Point and Bloomfield Hills were for wealthy assimilated Protestants, envied and detested by all.
My only experience with what you described occurred during Naval Academy summer training in Pensacola Fla,. when three of us, in uniform, went into a restaurant. One of us , Tony Moore, was black, and after being seated for a while, he was asked to leave. ( A then last vestige of the Jim Crow era there) The other two of us became indignant and started to make a scene. Tony asked us to calm down and just leave. We went back to the Air Station and I made a complaint to the Base Commander who expressed sympathy, but said that's the way it is. I was angry about that. Tony went on to beat me in the Intramural middleweight Boxing finals the next Fall. ( We're still friends.)
My strong impression is that there was then more willingness in the ethnic stews of cities like Detroit to judge people by their individual characteristics and tolerate superficial and group differences, and a good deal less hypocrisy about it all than there is in America today. Now if anyone expresses any disapproval of anyone in a favored group he/she is immediately labelled with one of the several "isims" so fashionable now.
I also notice that the most intense incidence of this new intolerance in the area where I live now is among the most intensely modern liberals of Marin County, North of the Golden Gate ( home of Barbara Boxer), and among the IT types on the Peninsula -- these are the most segregated areas in the Bay Area ! The complacent hypocrisy here is truly breathtaking. My impression is that Annapolis isn't very different - at least when compared to nearby Baltimore ( I travel there frequently.)
Individual characteristics and behavior matter a great deal. The relatively superficial group distinctions and identities, so emphasized today, don't, and the presumption that they do is itself highly prejudicial.. Judgments based on the actions of individual people of any such group do not necessarily mean any of the fashionable "isms" that infest our culture. In the same way the presumption that they do is itself a vivid manifestation of the very evils implied by the "Ism" labels themselves. This new intolerance is no remedy for the other forms of the intolerance it presumes to oppose,
The perversity of the present situation is a bit like something out of Orwell's 1984 or the Cultural revolution in China. Both involve the tyrannical application of false narratives used for political purposes generally different from the issues at hand.