I'm not sure when that changed, but I recall when I was younger (HA!) the neighborhoods in big cities were somewhat ethically varied.
Immigrants moved here, built their neighborhoods, the rest of us went to those neighborhoods for food, drink, parties, and visiting friends.
Last time I was in Chicago or San Fran "China Towns" I struggled to find anything in English or that would indicate in any way that I was in the US. I love that diversity and have thought that's the America we all loved.
Seems to me the racism and hatred started surfacing about the time Reagan came along to fuck us up.