Question for US Yahoo people...?

I can generally tell from what part of the UK a person is from by their accent - Londoner, Brummie, Scouser, Geordie etc...and I can also distinguish a Bronx, New England, Texan, and generally a Southern American accent. But can Americans distinguish say, East coast from West coast accents? I can't tell the difference between a mid western accent and one from Chicago. Are their big differences in accents? (I'm from the UK by the way)