Magnifying glasses do not always make matters clearer. There has been much talk about American English, in terms ancestral. Researchers have analyzed speech sounds and “derived” them with particularity suggestive of Bernard Shaw’s PYGMALION.
I have never pondered over any possibility to become my grandfather. Anyway, my grandfathers or grandmothers did not speak American, or actually any English, as far as I remember.
My father spoke some English, but he said he had an accent. If I wanted a grammar book, he would buy it for me, same for note books and other stationery, but he would not teach me.
He told me to pick the language on my own: I was little enough for that, a kindergartner. He was right, though he was a historian; and I chose American.
Back to deriving American English entire:
The main idea of the approach is that the origins of American English are somehow contained in the various regional dialects of British English.
AMERICAN ENGLISH, AN INTRODUCTION, by Zoltan Kovecses.
Ben Trawick-Smith makes an interesting point:
as well, we might think about the British as “talking American”.
He would include American English with “a larger continuum of Southern England-derived dialects”, he yet adds the idea is debatable. Feel welcome to read, WHEN DID AMERICANS STOP “TALKING BRITISH”?
What American English do we talk about? If we do not say, the American English of the 1900s, or 1800s, we say: contemporary American English.
The present-day form of the language originated in the USA. We always tell language origins by the countries or lands of emergence.
My theory is that humans have spontaneity to accompany reason, and always part invent own skill. It is impossible to ascribe American English, as it is today, to dialects of England or scholarly dictates.
American was taking shape already with the Declaration and Constitution. We can see the honor that behavior followed; the definite article begins to take on a cognitive form, in citizens of a state rather than always the citizens (thereof).
The Modal verb shall presents a scope to prefigure, and not to prescribe:
The trial of all crimes, except in cases of impeachment, shall be by jury; and such trial shall be held in the State where the said crimes shall have been committed.
Feel welcome to my grammar blog notes on modern American English and the US Constitution.
CONSTITUTION OF THE UNITED STATES OF AMERICA