How do ppl have accents?

[3 Sheets To The Wind]

Like i knows if u go to a area where they speak differant and lived there your accent would eventually change, but how does coming from differant parts of a country give you a accent? And how did it all start....?

imp: :rasta:

People that first populated those towns would have come from another country/place that used that accent and over the years it has just evolved and changed a little, like the words and things they used to use in Shakesperean times that we neglect in today's world