Historically, no. Two of the most striking distinctions between British and American English-- the treatment of postvocalic "r" * and the pronunciation shift of short "a"-- are British innovations that occured after the dialects split.
Ah but this is pronunciation as opposed to spelling. There are many people within the UK who, when speaking in their local accent or dialect cannot be understood by anyone outside of their communities. (I am one of them.) ;)
The original settlers in the USA during the 17th and 18th centuries were mainly people from the UK who spoke English from their neck of the woods. For more than two hundred years there was little communication between the two populations. I actually think that the American accent has some similarities to that used in the south west of England. Many of the original settlers came from that area, which would explain it.
Some words considered by we in the UK to be American English are actually original English words that were retained in the US but not here. In his excellent book "Made in America", the American writer Bill Bryson asks this question.
"Why did the Americans save such good old English words as skedaddle and chitterlings and chore, but not fortnight or heath? Why did they keep the irregular British pronunciations in words like colonel and hearth, but go down our own way in with lieutenant and schedule and clerk? Why in short is American English the way it is?"
Personally I think it was caused by the languages evolving separately at a time when there was little communication. This is no longer the case and the languages will once again merge due to increased worldwide communication in English.