B.B. King got his due in his lifetime, but (honestly) he was always more of a radio huckster than a real bluesman.
And just F.Y.I the "recording age" for country blues (solo accoustic blues, which in the early days meant either Texas or Delta) began pretty much in 1926. That was when somesuch type of microphone became cheap and portable enough to set up in makeshift studios around the dusty old south. Prior to that (starting in the late teens) blues records were mostly female singers (most notably the great Bessie Smith) backed by Jazz bands. Interestingly, the songs those groups sang were mostly from sheet music transcribed by W. C. Handy, a black music professor from Chicago who around the turn of the century was traveling through the south and transcribed a whole lot of songs of this new musical style that he'd never heard before.
A lot of the first generation of bluesmen had some commercial success. Prior to the depression, there was a sizeable black middle class in northern cities, and they were the primary purchasers of blues 78 rpm records (though this was still a niche market, jazz had a bigger fanbase and a MUCH bigger crossover appeal to whites). Blind Lemmon Jefferson was actually wealthy for a while, and owned three cars despite not being able to drive.
Of course the record industry was as evil back then as it is now, and would keep uneducated performers in debt to force them into recording new songs (this is exactly why record labels like to pay rap stars in cars and houses rather than actual cash) and a few years later Lemon froze to death in his Chicago apartment.
But most importantly, this all suggests that Ray is black. Discuss.