Janet McTeer
Janet McGeer is a marvel to watch in this movie. Small wonder that she received an Oscar nomination. She plays a role that is almost the polar opposite of her personal background and training.
If you didn't know anything about McTeer, you would probably assume that she's an American and perhaps even a Southerner. In fact, she was born and raised in southern England and graduated from the justly famous Royal Academy of Dramatic Arts (RADA) as a classically trained actor. For years, she was essentially a stage performer who worked in Shakespearean and other classic works in Britain. In Tumbleweeds, she emerges as a rough-around-the-edges, unsettled, flighty, oft-married, insecure, but always loving Southern gal. She sustains the Southern accent, nuances, body language and blowsy demeanour throughout, a remarkable achievement considering her background.
A lot of British actors seem to adopt American accents quite easily, but this role reversal doesn't seem to work very well the other way. Renee Zellwegger pulled it off brilliantly for the Bridget Jones movies, and Brad Pitt played a loonybird Irish gypsy in Snatch with great effectiveness. Other significant examples don't spring to mind.
Anybody know if other American actors have effectively achieved this linguistic reversal?