Bill Carver was a D.A. who prosecuted the organization called the Thunderbolts. In retaliation they tried to have him assassinated, but only managed to kill his younger brother whom Bill took to the fair. At the funeral the sniper tried once more only to fail. As Bill struggled with the assailant, a lightning bolt struck both of them. The assassin was instantly killed, but Bill Carver survived long enough to under go an experimental process that seemingly saved his life. The process gave Carver super speed, and he decided to get revenge for his brother. In a symbolic manner Carver took the name Thunderbolt, the name of the group he sought after.
It was later discovered that lawyer Big Ben Donovan was responsible for Carver's hit. Carver also learned that his ability was not only giving him super speed but also rapidly aging him. In a final climatic fight, Carver battled Donovan to the death. A gun that Donovan was holding went off and apparently shot its owner. Carver disintegrated from his power's side-effects, content with having found justice for his murdered brother.
Thunderbolt was created by Roy Thomas and Gene Colan in 1970 and first appeared in Daredevil #69.