The Blues was seen as an authentic music.
The British Blues boom started back in the fifties with Chris Barber. That gave rise to Alexis Korner and Cyril Davies with Blues Incorporated which was a breeding ground for the Rolling Stones.
After the initial British Beat boom of the mid sixties with bands like the Stones, Yardbirds, Animals, Graham Bond, Them and Pretty Things had moved into pop and psychedelic there was a second wave of Blues Bands. They focused around John Mayall’s Bluesbreakers.
My Favourites were
Cream
Fleetwood Mac
John Mayall
Chicken Shack
Keef Hartley
Aynsley Dunbar
John Dummer
Hendrix did a bit of Blues too!