If it's just a matter of a white musician using black music influences How about Louis Moreau Gottchalk? He was hugely popular in the mid 19th century.
> If it's just a matter of a white musician using black music influences How about Louis Moreau Gottchalk? He was hugely popular in the mid 19th century. <
Much less popular, however, than Stephen Foster. And at least Foster made the list of the top 100 influencers!