When Americans developed their own "American accents"?

Question

Historically, how and/or when did the colonists, after breaking away from England, did they develop their own "American accents"? I've always wondered.

serious answers appreciated. :)

Answer 1

it just happened over time... when you have so many europeans in the new world and they all start to speak english they end up creating their own accents

Answer 2

Over time mixtures of different cultures and even separation can create a new accent. That's sorta how Portuguese got made from Spanish.

Answer 3

Modern British English is based primarily on the London variety of English. The English used to have many accents. This was because many English farms and villages were isolated from each other and an English peasant living in one locale often had no contact in his lifetime with an English peasant living in another locale only twenty miles away.

In the late eighteeenth century, as transportation and communications began improving, the London dialect began spreading to other parts of England, replacing local hayseed dialects that had previously been spoken there.

However, the thirteen colonies were settled in the 17th and early 18th centuries before London English began expanding. Consequently, many older, regional accents of English survived in the colonies.

Had America remained part of the British Empire, the London standard of English almost certainly would have exercised a stronger influence on American English but America became independent by 1783.  It's interesting to note that Canadian English has some British-like pronunciations such as "proh-gress" for progress and  "lef-tenant" for lieutenant which American English doesn't have.  

The London variety of English, a non-rhotic (or r-less) form of English, had some influence only in the northeast, in New Jersey, New York and New England. That's why people there often pronounce words like garden, market and park the car   as "gah'den,"  "mah'ket" and "Pahk the kah" while pronouncing words like  saw, drama and Cuba like "sawr," "drah-mer" and "Kooh-ber." This is a natural characteristic of non-rhotic (i.e. London) English.

Historical linguists theorize that the reason London English was stronger in the Northeast was because New Yorkers and New Englanders had stronger trading contacts with the mother country than American colonists living further west and south.

In the South and the West, American English has remained more conservative (rhotic) in a lot of ways still preserving the hard 'r' sound that was common everywhere in 17th century English.

The nasal sounds found in American English to a greater or lesser degree probably already existed in the original 17th century English, but like intervocalic 'r,' they eventually disappeared in British English because London English was non-nasal.