Actually the English spoken in the US is much closer to the "original", meaning the common dialect spoken on both sides of the Atlantic in the Colonial Era.
This is a furphy. There was no "original" English in the colonial era, there were dozens, possily hundreds of them. How you spoke depended on which part of England (or Ireland, Scotland, Wales etc) you came from.
American English (and modern "English" English, for that matter) is a homogenised version of all the contributing dialects and accents, as most modern languages are.