IN THE SUMMER OF 2010, just hours after meeting with Ken Burns about his addendum film to “Baseball,” I wrote an open letter to him. My pitch: “America’s documentarian” has famously created films about some uniquely American institutions and art forms, including “Jazz.” Why not take on an American art conspicuously missing from his catalog? Namely, the comic strip — as well as perhaps newspaper cartoons more broadly.

Little did I know it at the time, but a former Burns hire had begun undertaking a variation on that theme.

The month before I wrote the piece, I met and listened to such aging comics legends as Jerry Robinson and Joe Kubert — at a Jersey City industry gathering — and so I urged Burns that such pioneering cartoonists needed to be interviewed sooner rather than later.

Fortunately, Emmy-winning documentarian Michael Kantor, working with Emmy-nominated collaborator/historian Laurence Maslon (“Make ’Em Laugh: The Funny Business of America”), was then endeavoring to talk to such storytellers as Robinson (co-creator of the Joker), and Joe Simon (co-creator of Captain America), and former DC Comics editor/writer Carmine Infantino.

By this past spring, all three of those cartoonists had died. But in a three-hour film that debuts tonight on PBS, titled “Superheroes: A Never-Ending Battle,” their captivating faces and engaging memories joyously live on as they recount their field’s early years.

And that’s part of what makes “Superheroes” such a treat. The film doesn’t simply trace a course across the span of cape-and-cowl comics — from Superman’s post-Depression ’30s birth by a couple of Cleveland teens, to Brit Henry Cavill’s embodiment of the “Truth, Justice and the American Way” character in this past summer’s hit film, “Man of Steel.” The documentary captures the flesh-and-blood experiences as conveyed in interviews by such great talents as Jules Feiffer and Ramona Fradon, Neal Adams and Jim Steranko. And the entire project was launched after interviewing one other legend, the greatest living ambassador of comics: Stan Lee.

The Emmy-acknowledged team of Michael Kantor (left) and Laurence Maslon collaborated on the documentary “Superheroes,” which debuts Tuesday night on PBS stations. (©Stephanie Berger via PBS./Stephanie Berger Photography. All Rights Reserved .)

The man who a half-century ago began co-creating such iconic and oft-alienated characters as Spider-Man, Iron Man, Hulk, X-Men and the Fantastic Four was the first interview they conducted for the project, more than three years ago, Kantor tells Comic Riffs by phone. “He was 87 at the time, and just bubbling with energy.”

Maslon came to the project as a lifelong comics and pulp-fiction geek. Several decades earlier, as a young man, he’d even got Lee and Jack Kirby — those twin Marvel masterminds — to sign a Galactus figure he’d created, at a comics convention. Kantor, by contrast, launched into “Superheroes” as less of a comics expert, but was eager to immerse himself into industry stories both on the page and straight from each source’s mouth. And once they got Lee to sit for an hour or two in front a green screen, they knew they had the beginnings of something special.

“I am shocked he hasn’t received a Kennedy Center Honor,” Kantor tells ‘Riffs of Lee, who turns 91 in December.

“The Honor’s for performing arts,” Maslon says. “Maybe a National Medal of the Arts. ... He’s the Homer of the 20th century. What writer wouldn’t want a career with his reach and opportunities and immortality?”

(Lee notes to Comic Riffs that he indeed received the arts medal from President Bush, in 2008. “Now,” he says wryly, “I’m waiting for my Pulitzer and/or Nobel.”)

One reason Lee deserves such honors, Kantor and Maslon believe, is to officially recognize his profound contribution to American culture. But such prominent prizes serve a second function, as well: Sixty years after Congress went after superhero and horror comic books as detrimental to America’s youth, such lofty laurels help underscore the larger social legitimacy and power of comic books in 2013.

“With great power,” Kantor and Maslon like to say of this global industry, tweaking Lee’s immortal line, “comes great respectability.”

As Disney prepares to release “Thor 2” next month — the latest feature film in a Marvel movie franchise that has grossed billions of dollars — there’s no doubting the financial muscle and massive reach of Spandexed crimefighters. But the great power of comics has often been under attack, undercut and over-leveraged. Kantor and Maslon deftly track that nine-decade dynamic of social prominence and setbacks in “Superheroes.”

Smilin’ Stan Lee and friend. (Reed Saxon / AP)

The filmmakers see the lives of Lee and Kirby, Simon and Robinson — like the superhero comic itself — as quintessentially American tales. Like Cleveland teenagers Jerry Siegel and Joe Shuster — who effectively birthed the superhero comic-book industry in the late ‘30s with their seminal creation, Superman — these Jewish writers and artists became success stories through invention and imagination at the dawn of their field’s explosion, the documentary puts forth.

“We focus on an art form and cultural expression that’s uniquely American,” says Kantor, who says this storytelling approach was emphasized to him early in his career when we worked for Burns. “What does superhero comics say about us as a people, unlike French graphic art?”

Liev Schreiber — a veteran of comic-book films himself — hosts the new PBS documentary “Superheroes.” (©Stephanie Bergervia PBS ./Stephanie Berger Photography. All Rights Reserved.)

Superhero comics, Kantor notes, have historically relied on two tenets that he says are themselves quite American: “Might makes right. And that we’re doing [something] for the right reason. We kind of like to see ourselves that way.”

Taking a cue from Burns’s own documentaries, the “Superheroes” filmmakers smartly set their narratives against the shifting tectonic plates of American life — from war to peacetime politics, from rights movements to changing lifestyle mores. Superman and Batman, star-spangled Wonder Woman and Captain America spike in popularity during World War II but ebb in sales shortly after, for instance, and Marvel’s flawed heroes gain traction in the turbulent ‘60s.

“That’s the double helix of this film’s DNA,” Kantor says.

“My hope is that the documentary will reach both comic-book fans who are naturally interested,” Kantor continues, “and maybe more important, that we more broadly [reach people] who care about American cultural history.”

As a barometer of the potential audience, “my dentist is my lodestar,” Maslon says. “He’s 50 and read comics as a kid, but gave them up in the ’70s. He has kids now, and they read Deadpool and Winter Soldier, but [Dad] doesn’t know what they’re about — while his kids don’t know Bucky. ... So with this film and the [in-depth companion] book, we try to have the bandwidth to be a bridge between generations.”

Meanwhile, what strikes Kantor as another peculiar American trait is not always caring deeply enough about the source of a creation. “We love our entertainment,” he says, “but we often take for granted, and don’t fully appreciate, those who are laying it on the line for us -- people who were not getting paid what what they deserved and followed their career path and ended up drawing comics.

Michael Kantor (Jayme Roy/.)

“I just loved that we celebrated those guys and their contributions ... ,” Kantor says of the comics pioneers who speak in the film. “We could have tried to get Nicolas Cage and Jerry Seinfeld” — celebrities noted for their Superman fandom — “but we wanted the creators.” (Among the dozens of on-camera interviews, the film — hosted by superhero-movie veteran Liev Schreiber — features such incisive contemporary writers and artists as Mark Waid, Michael Chabon, Todd McFarlane, Len Wein, Trina Robbins, Joe Quesada, Jim Lee and Geoff Johns. Also featured: Such superhero performers as Adam West and Lynda Carter, as well as “Watchmen”/”Man of Steel” director Zack Snyder.)

The two voices Kantor most wishes he could have got (both are deceased) are comics giants: Kirby and Will Eisner. It’s worth noting that the film does not wade deeply into the still-brewing spats over rights and royalties — even as the Kirby estate continues to seek greater compensation through the courts.

“We aren’t here to decide that,” Kantor says of adjudging which creators have been slighted. He says it’s especially unfortunate that some comic fans still take sides over who deserves more or less credit in the powerhouse pairing of Lee and Kirby.

But then, Kantor says, “that is another one of those never-ending battles.”