I played all through Arkansas, Mississippi, Louisiana, Alabama and around in Kentucky and places, but I never played in Texas, but I played all over the cotton belt countries - Howlin' Wolf, interview with Pete Welding, Chicago, ca. 1967, I Sing For The People: An Interview with Howlin' Wolf, Down Beat, 14 Dec 1967
I just read about this forthcoming book from Elijah Wald: http://www.elijahwald.com/dozens.html I've pre-ordered it, hopefully I can survive Messrs. Cameron & Osborne's viciousness long enough to pay for it when it finally gets released. If it's anything like Mr. Wald's other books, then it'll be fifteen quid well invested.