Side question. I’ve been always wondering: how has the American accent evolved? Where does it come from? Is there any region in Britain that sounds American? Or did just evolve independently as a mix of British and something else? And: since when is it that different? Did Lincoln had an American accent?!
There's not really any such thing as an "American accent" or a "British accent," particularly when you're looking at the evolution of accents. Accents tend to evolve based on regional tendencies; what people refer to as "General American" (effectively the Midwestern US, but not including the Northern Cities Vowel Shift) and "Received Pronunciation" are accents that lack any recognized regionalism markers, such as the…
It used to be even more pronounced, with neighbouring villages in England having distinct accents. Nowadays, i suspect that the differences are disappearing - although perhaps some will always remain.