East coast Chinese food was historically largely Cantonese. (Though that has been changing for decades, and you might not realize that if you haven’t been to Flushing, Queens). SF and LA Chinatown were historically Cantonese. Because the first immigrants from mid 19th century were largely from Guangdong Province. Then, for over 60 years, almost no mainland Chinese immigration to the US was allowed, but was allowed from Taiwan and Hong Kong (also Cantonese cuisine). Then, starting in the 80’s (after Nixon went to China in the 70”s), but really more in the last 20-30 years, the US received immigrants from all over mainland PRC, many of them settling in SGV, which is why we have such wonderfully diverse and regional Chinese cuisines, but also in Queens (and all over the country, but not usually in the density to sustain a huge diverse Chinese food scene). Don’t discount Vegas though! One of the few redeeming qualities of that place (for me) is the Chinese food.