There are a ton of different accents in the US. Wherever i go... people ask "where are you from" or they say "You're from Chicago aren't you".

At a project in Europe about 5 years ago i met people from allover the world who worked on a yacht. There was a girl there from the Chicago area so all of her ship mates were familiar with the "Chicago Accent". Up until that point i had no idea that i had an accent :). I had a similar experience in New Orleans when i worked with a guy who lived in Chicago and recently moved to New Orleans.

There was a guy from London, one from The Isle of Man, A Dutch guy from South Africa and one from Australia. At times it was like their accents had all mingled into something unique/similar but other times you could clearly tell the difference. I catch myself sometimes.. my speech pattern will change when i am talking to someone with a Hispanic accent. I only have to be talking to them for a few minutes and the next thing you know i start to sound like them. I have a cousin who lived in Chicago up until a few years ago. She is 36. She now lives in Louisiana and her, her 2 children and her husband all sound different when they talk now.

I can imagine a group of settlers bumping into a native tribe at some point in history or maybe a French woman meets and marries a Spanish man and a few generations later we have a very distinct version of English in a particular part of the country.