Leadbelly
Huddlie William Lebetter (1888-1949) - better known as Leady Belly (two words!) was the darling of the folk circuit and the king of the 12-string acoustic guitar. His style is really unlike anyone else's from the pre-war or post-war era.
He played a large Stella 12-String that he tuned down/up in standard tuning - I think. If you try to play along to Lead Belly's recordings, you may have trouble getting in the same key - this is why.
Some dismiss Lead Belly when it comes to country blues since he recorded so many different styles of music including Gospel & Folk. If you want to play blues on the 12-String, Lead Belly and Blind Willie McTell are among the few you can listen to.
My Favorite Lead Belly Songs
(1) Good Morning Blues
(2) Mr. Hitler
(3) Midnight Special
(4) Goodnight Irene
(5) Where Did You Stay Last Night?
(6) Rock Island Line
(7) Jim Crow Blues
(8) Silver City Bound
(9) CC Rider
(10) House of The Rising Sun