Despite the age difference — he was 42; she was 23 — she said, "We were absolutely right for each other."
After producer Harry "Pop" Sherman ceased production of the Hopalong Cassidy films in 1944, William Boyd set about purchasing the rights to the old movies and the Hoppy character.
To help raise the $350,000 to purchase the rights, the Boyds sold their ranch home north of Malibu and moved into an apartment in Hollywood.
"We were," Grace Boyd recalled in a 1991 interview with The Times, "down to absolutely nothing."
In 1946, William Boyd formed his own production company to begin turning out new Hoppy movies.
But the Boyds' investment paid off in a big and unexpected way.
In 1948, the old Hoppy films began appearing on KTLA-TV Channel 5 in Los Angeles and on a station in New York City. NBC soon began airing them nationally and Boyd then started making new 30-minute episodes for television.
As America's first real television hero, the wise and tough cowboy with the friendly grin became a show business phenomenon.
More than 2,000 products were manufactured bearing Hoppy's name and likeness, and Boyd, as Hoppy, appeared on the covers of Life, Time and Look magazines. During a 26-city tour, a million fans turned out to see him.
"I made a point of being in the background," she said in the 1976 interview. "As far as the kids were concerned, Hoppy was Hoppy. He didn't have a wife or family. When the young ones would ask, 'Who are you?,' I'd say, 'I'm Hoppy's mommy.' "
William Boyd retired from the screen in 1953 and died in 1972 at 77.
At a loss after his death, Grace Boyd began her more than 35 years of volunteer work at the hospital in Laguna Beach where her husband had spent his final days.
But Hopalong Cassidy always remained part of her life, including winning a two-decade legal battle stemming from a copyright infringement suit, and appearing at Hoppy tributes.
"Everybody I talk to is looking for a hero," she said at the Lone Pine Film Festival in 1995. "They say, 'If only we had Hoppy again,' or somebody like that. The children don't have role models. Who do we have?"
Boyd had no survivors.
A private service was held Thursday at Forest Lawn Memorial-Park, Glendale, where she was interred next to her husband.