Brandon Stoddard, the longtime ABC exec who shepherded such landmark longform productions as “Roots” and “The Winds of War,” died Monday after a battle with cancer. He was 77.

Stoddard had a 25-year career at ABC, rising to entertainment president from 1985-89. He spent another six years as head of ABC Prods. before stepping down in 1995.

During his long run, Stoddard was an instrumental player in steering ABC’s success with large-scale miniseries productions. None was a bigger gamble than “Roots,” a gritty historical look at the journey of Africans into the slave trade in America that aired over eight consecutive nights in January 1977. The production and the impact it had as a cultural event remains a milestone for the medium.

Stoddard was inducted into the Television Academy Hall of Fame in March. After leaving ABC, Stoddard spent 10 years teaching graduate students at USC’s School for Cinema and Television.

Stoddard was a mentor and friend to a generation of TV execs including Bob Iger, producers Marcy Carsey and Tom Werner and Ted Harbert, now chairman of NBC Broadcasting.

“In many ways, I owe my career to Brandon. He taught me how to read a script, how to talk to writers and to above all, revere great characters and stories,” Harbert told Variety. “And we laughed.”

Iger, chairman-CEO of Disney, succeeded Stoddard as ABC Entertainment president in 1989.

“Brandon was a true maverick who was instrumental in transforming prime time television. His influence continues, and he will be missed by everyone who had the good fortune to know him,” Iger said.

Gary Levine, exec VP of programming at Showtime who worked with him at ABC in the 1980s and ’90s, recalled that one of Stoddard’s guiding principles for development was to respect the audience.

“In spite of the fact that Brandon was one of the smartest creative execs ever to work in television, he never looked down on his audience. He insisted on aiming high, which was rare for broadcast television,” Levine told Variety. “The results: ‘Roots,’ ‘China Beach,’ ‘Roseanne’ and ‘Thirtysomething,’ to name but a few, speak volumes about his taste, his craft and his fierce belief in challenging the viewers.”

Stoddard grew up in Southport, Conn., and attended Yale University. He initially pursued a career as an actor, but got discouraged and veered in law. He wound up in advertising at BBDO, which eventually led him to join ABC in 1970 overseeing daytime and children’s programming. He developed the enduring “Schoolhouse Rock” shorts designed to teach kids basic history, English and civics lessons such as how a bill becomes a law.

As he rose through the ranks at ABC, Stoddard moved into the longform arena where he helped bring “Roots” to the screen. ABC under Stoddard delivered epic, ambitious productions that were seen as “novels for television,” drawing on Stoddard’s high-brow taste in literary material and his equally strong skill at adapting it for mass appeal. Among the ABC productions of the era were “Rich Man, Poor Man,” “QBVII,” “The Thorn Birds” and “Masada.”

The 1983 WWII saga “The Winds of War” starring Robert Mitchum marked a peak of audience size and scope of the storytelling. But the 1988 sequel “War and Remembrance” marked the beginning of the end of the mega-miniseries as it was costly and not as successful as its predecessor.

Beyond the miniseries, Stoddard championed telepics that broke ground on controversial subjects, such as the nuclear drama “The Day After”; “Something About Amelia,” which tackled incest; and “Friendly Fire,” about the aftermath of the Vietnam War.

He also oversaw ABC’s feature film development efforts in the early 1980s. The division yielded the Oscar-nominated “Silkwood,” which started out as an ABC TV movie project; “The Flamingo Kid”; and “Prizzi’s Honor,” among other titles.

Stoddard was named ABC Entertainment president in 1985. While Stoddard was head of programming, ABC fielded such hits as “Roseanne,” “The Wonder Years,” “Moonlighting,” “Thirtysomething,” “China Beach,” “Max Headroom” and “Full House.” He also greenlit the pilot for “Twin Peaks” and oversaw the production of the cult-fave “My So-Called Life” during his time at ABC Prods.

Later in life, Stoddard turned to painting and had an exhibition of his works at Santa Monica’s Bergamot Station.

Survivors include his wife, Mary Anne Dolan, and two daughters.

Here’s a clip of Stoddard discussing the surprise success of “Roots” in an Archive of American Television interview with Variety‘s Brian Lowry: