Where is Taishanese the dominant divergent of Cantonese phonology most spoken in North America?
Cantonese phonology:  Yue dialects in other parts of Guangdong and Guangxi provinces, such as Taishanese, may be considered divergent to a greater degree. Taishanese:  In the late 19th century and early 20th century, a significant amount of Chinese emigration to North America originated from this four-counties area called Sze Yup, making Toishanese a dominant variety of the Chinese language spoken in Chinatowns in Canada and the United States.
Chinatowns