For someone of English origin who likes American folk music there can be only one, and that's Lonnie Donnegan.

He took some flack from American folk fogies who were kinda jealous 'cos he made a lot of money at it. But he doesn't get the credit that he deserves for introducing a whole generation of Brits to American folk music.

Not only that, he introduced them to the pleasure of making their own music and not relying totally on the canned stuff.