What causes different dialects from area to area.?

Question

I live 2 hours from Kansas City and they all talk like me there. I live 4 hours from St. Louis and I can spot someone from the Lou as soon as they open there mouth. They have an obvious accent to me and are only 4 hours away.

Answer 1

It's a very interesting topic, you should read up on it.  Isolation and time are two major factors in the development of regional dialects.  A language evolves with its speakers.

Answer 2

People talk like the people around them. Over time, small changes in the way people talk accumulate, and eventually a group that is separate from another will speak differently.

Answer 3

historically one reason for dialects is the different classes in society. the elite class has a different accent/dialect than the lower classes.

politics and society constantly curves the dialects today. even culture contributes to the change in language.