@LutherVan, England had a lot more history and time for traditions, accents, etc. to develop and splinter off. So much so that going a short distance could mean a sea change in language, foods, and mores. Meanwhile, big swaths of the US were colonized by the same cultural group of people. Southern slaveholders (and their slaves) sweeping west across the South. The Northern British borderers starting out in the Appalachian backcountry and moving west through KY, TN, the Ozarks, AR, and OK. Nordics and Germans immigrating and colonizing a big swath of the Midwest.
It’s the same with Australia and parts of China or India. Australia is much bigger than Fujian province in China or southern India, but there’s a far bigger profusion of languages in both Fujian and southern India (various dialects of Tamil, Kannada, Malayalam, etc.) than in all of Australia.