That's correct. The first influx of Chinese immigrants were mostly from the south. After the CCP took over, immigration from the mainland basically ceased. During the 60s-80s most of the Chinese immigrants that were not from HK were from Taiwan.
Immigration from the mainland started picking up after the Cultural Revolution in the late 70s / early 80s through now.
"Chinese" food in the US is mostly Cantonese food. Only fairly recently have you seen an uptick of non-canton style food. The latest trend is Sichuan / Chongqing style of cuisine (spicy!).
My favorite Chinese regional cuisine is Xinjiang cai (food of the uighurs, China's muslim minority group). Very tasty - lots of bbq meats, delicious noodles, and spicy. Also bonus that its halal/kosher.
Chinese food in the US is fairly diverse (and has been for a while). Hunan food is, IIRC, quite common in New York and accounts for most of what New Yorkers think of when they conjure up images of Chinese food. Even in SF, places like Henry's Hunan have been around for a while (early 70s). If you go to the LA area you'll find a large proliferation of Taiwanese restaurants (which are relatively scarce in SF).
Immigration from the mainland started picking up after the Cultural Revolution in the late 70s / early 80s through now.
"Chinese" food in the US is mostly Cantonese food. Only fairly recently have you seen an uptick of non-canton style food. The latest trend is Sichuan / Chongqing style of cuisine (spicy!).
My favorite Chinese regional cuisine is Xinjiang cai (food of the uighurs, China's muslim minority group). Very tasty - lots of bbq meats, delicious noodles, and spicy. Also bonus that its halal/kosher.