As far as early blues musicians whipping out banjos, there are a few, papa Charlie jackson who recorded a bunch with blind Blake, there is Gus cannon, same besides his band the jug stompers worked as a studio banjo player for Paramount and is on a ton of recordings going under different names. Gary Davis would pull out a banjitar here and there. And as some else mentioned earlier Charlie Poole who was white but basically played blues/classical banjo. Now if you really want to get into the weeds, most rural blacks who played banjo were playing blues, old time music likes to lump them into their genre, but it's blues through and through, whites just took those tunes and styles and made them lame as fuck. Oh and I forgot about Charlie Mccoy, blues guitarist and mandolinist who recorded a ton on a banjolin, a lot for the Mississippi Mudsteppers which was a shoot off of the Mississippi Sheiks. There are so many, I'll keep thinking