According to Wikipedia;
The electric blues is a type of blues music distinguished by the amplification of the guitar, the bass guitar , and/or the harmonica. Electric blues is performed in several regional subgenres, such as Chicago blues, Texas blues and Memphis blues.
The electric blues first emerged as a fully-fledged genre in the mid-1940s. The initial wave of U.S. electric blues musicians inspired the British blues scene of the 1960s, which included artists such as John Mayall & the Bluesbreakers, Cream, Eric Clapton, The Yardbirds and the first incarnation of Fleetwood Mac, as well as rock groups such as The Who, Led Zeppelin and The Rolling Stones.
Though one of the most famous and arguably the best guitarist, was Stevie Ray Vaughn. He Brought the music of electric blues to a new level, inspiring and exposing it to a vast crowd which made this genre even more popular then it was previously.
John Mayer was first inspired by Stevie Ray Vaughn's playing though he took a more pop-sounding route. But later, he came back to his more bluesy roots with John Mayer Trio.
Electric blues artists include:
John Lee Hooker
B. B. King
The Rolling Stones
The Allman Brothers Band
Kenny Wayne Shepherd
The White Stripes
Stevie Ray Vaughan