It's been said, often, that the US and Britain are two countries forever divided by a common language. And there are folks who will tell you that the language is not at all common, that it's two languages, and that you can only understand the other if you've been exposed to it quite a bit. I recall trying to share Monty Python and the Holy Grail with my kids, who refused to watch because they couldn't understand what was being said. Their loss.
There's a big ocean between the two countries, so it's no wonder that the pronunciation has diverged. But the United States is such a big country that Americans pronounce words differently depending on the area they are from. Laurence Brown has spent the last ten years contrasting Britain with America. In this video, he tells us about the American words that are not only pronounced differently from the British version, but also differently from other Americans. I'm sure there are some here that you (if you are American) pronounce in your own way. There's a 75-second skippable ad at 3:19.