Yea, I was familiar with the name -- on his first album Dylan covered "See That My Grave Is Kept Clean".
Dylan also named one of his most literarily analyzed songs "Blind Willie Mctell". The first line is "I've been all through East Texas..." Mctell was from North Carolina, but I found out that Jefferson was indeed from East Texas. It's possible Dylan used Mctell because Jefferson's a hell of a word to rhyme with over five verses.
Hmm...can't remember anyone pointing that out before, but with the sheer volume of stuff written about Dylan, and the twelve monkeys with twelve typewriters theory, I'm sure someone has.
The little I've heard of Jefferson makes him a more likely candidate. The chorus goes "But I know no one could sing the blues like Blind Willie Mctell". Mctell was interesting, but his stuff was more good-time more Saturday-night-having-a-drink-on-the-porch stuff, often very funny, not really a likely inspiration for an epic ballad.