He played a key role in the U.S. Supreme Court case Hernandez v. Texas by fighting to end the exclusion of Hispanics from jury service.
He studied at the University of Texas on a scholarship after graduating as the valedictorian of his high school.
He was a legal advisor to the League of United Latin American Citizens and the American G.I. Forum working for desegregation.
He married three times and had two children with his second wife.
John Herrera also worked for the desegregation of Mexicans in America.