Parker trained with William Chow while serving in the Coast Guard and attending Brigham Young University, and in 1953 he was promoted to the rank of black belt.
Parker, seeing that modern times posed new situations that were not addressed in Kenpo, adapted the art to make it more easily applicable to the streets of America.
[5] The other black belts in chronological order up to 1962 were James Ibrao, Ben Otaké; Mills Crenshaw, whom Parker authorized to open a school in Salt Lake City, Utah, in late 1958 (which later became the birthplace of the International Kenpo Karate Association, or IKKA); Tom Garriga; Rick Flores; Chuck Sullivan; Al and Jim Tracy; Mark Georgantas; John McSweeney; and Dave Hebler.
He was well known in Hollywood, where he trained several stunt men and celebrities, most notably Elvis Presley, to whom he eventually awarded a first-degree black belt in Kenpo.
He left behind a few world-renowned grand masters: Bob White; Richard "Huk" Planas; Larry Tatum; Ron Chapel; and Frank Trejo, who ran a school in California prior to his death.
[2] After receiving his brown belt in Kenpo, he moved to the US mainland to attend Brigham Young University, where he began to teach martial arts.
These martial artists were known for their skills in arts such as Five Family Fist Kung Fu, Splashing-Hands, San Soo, tai chi, and Hung Gar, and this influence remains visible in both historical material (such as forms that Parker taught in his system) and current principles.
Parker drew comparisons in this and other books between karate (a better known art in the United States at that time) and the Chinese methods he adopted and taught.