B.B. King introduced many of my generation to The Blues. He became hugely popular in the late sixties when I first heard him at San Francisco's Filmore Auditorium. He later claimed that concert in 1967 was the first time he ever played before a white audience. Thanks in large part to B.B. "hippy" and college venues all over the country opened up to many great Blues musicians who were previously unknown to white audiences; James Cotton, Magic Sam, Freddie King, Albert Collins, to name a few.
He was a great musician and a great ambassador for The Blues.
As an aside John Hiatt, who wrote the title track on the Riding With the King album, is a superb songwriter and musician in his own right who is worth a little research if you haven't already heard him. .