rhoticity in american english
1) an r-ful (or "rhotic") pronunciation: New
York
2) an r-less (or "non-rhotic") pronunciation: New Yawk
• When the English colonies were founded in America, the prestige pattern in England was to pronounce all r's.
• During the 18th century, the prestige form in England developed the r-less pronunciation that is still standard in many English dialects today, and is in fact the prestige pattern.
• On the Atlantic seaboard, in continual contact with England, this prestige form was widely adopted as well, so that port cities such as Boston, New York, Charleston (South Carolina), and Savannah (Georgia) developed an r-less prestige pattern, as did British colonies settled later than the Americas, such as South Africa and Australia.