Shouter,
I should mention that John Jackson lives nearby in the Washington, D.C. area. Is he authentic? Gee, I don't know. Does it matter that he learned his licks off of records (he's old enough to remember records, even 78's)? He can play the blues. There is also a group that gets together each Saturday to sing and play the blues, mostly acoustic. They sing to honor Archie Edwards (I hope that's the right name), a local barber who was a likely to pick up his guitar as to pick up his scissors.
Baltimore has a "blues" Society. I am not real familiar with them, but I think they're focus is more electric blues. A local pub, The Cats Eye Pub, features blues, mostly electric. They frequently have jams on Sundays. There is a restaurant in the suburbs whose name escapes me that also features live blues performers.
Roger in Baltimore