Re: How do certain areas develop their own accents?

How do certain areas develop their own accents?
Lindsay, that is a very good question. 
Let me rephrase the question in a way that might help explain the answer.
How are certain areas developing their own accents ?
Language is very much a biomorphic entity.
It lives and changes over time in response to contact with other languages.

In the beginning, and there are many beginnings, A group of people will 
share a language that is homogeneous.
Over time this group will come in contact with other languages which 
influence and thereby change the nature of the original language.

Sometimes a group of people will be isolated from other languages and the 
language will not change over time. There are many factors which can 
affect regional accents.
The environment ( temperature, insects, etc..)
Politics
Religion
Cross-cultural contact
The list is long and predictable.

Let's look at English:
Northeastern U.S. English is spoken by Americans of Southern European and 
Arabic/ Mediterranean descent. Their original languages influenced and 
changed their english.
Southern U.S. English is spoken by people of English and Celtic descent.
Northern States had alot of Swedish and Nordic peoples who also had a lot 
of contact with Native American peoples, producing that distinctive 
English common in the Dakotas, Canada, and surrounding areas.
The native Texan accent is a product of German and Scottish settlers in 
contact with Spanish Speaking Mexicans and Caddoan Speaking Indians.
 
Northern people in all countries tend to be more nasal and speak more 
quickly than southern people. We assume this is due to colder weather 
having an effect.

English of Shakespeare's England sounded more like English you might hear 
in Alabama than the English you will hear in England today.
Wierd , huh ?

There are interesting examples of regional accents and pockets of 
linguistic isolation all over the world, I encourage you to study this.

Remember Mutiny on the Bounty ?
Pitcarin island is still there, and the people on that island still speak 
English the way it was spoken when those British sailors arrived on the 
island more than 125 years ago.

Tangerine island english is basically the english of the pirates who 
visited and lived there so long ago, it's very interesting to hear.

I hope I have been of help to you and have fun with your studies !