How is a new accent born?

Accents develop through isolation. New ones are less likely precisely because we are so much less isolated today. We move around so much more than people used to, there is more and more intrusive media. You could easily go a whole day in Dallas without hearing a Texas twang or in Atlanta without hearing a Southern drawl.

In the past, they denoted not only place isolation, but economic isolation of a particular group.

We are indeed less isolated, but can’t the same be said for colloquialisms? New ones of those are created and probably serve the same “purpose” as accents. When I moved to Seattle from Savannah and someone told me to go to the store and pick up a half rack I had no idea what they were talking about. But then when I said that I was fixing to do something they just looked at me blankly.

Why, hush my mouf’, ptb, y’all is so right!

i think the english language is like a giant game of telephone…=]