Before high schools taught about the Holocaust, before there were dedicated museums and before “Schindler’s List,” kids learned about the horrors of Hitler from comic-book superheroes.

At a time when most adults considered such fare brain-rotting junk and the topic of genocide too taboo to discuss openly, the largely Jewish comic book industry was quietly educating a new generation about the Nazis’ atrocities. Comic books featuring superheroes such as Captain America and with titles like “Blitzkrieg” and “War Is Hell” — their covers splashed with exclamation points and sound effects — often tackled the deadly serious subject matter inside.

Now this often-ignored legacy has been pulled out from the plastic sleeves of history in “We Spoke Out: Comic Books and the Holocaust,” a collection of comic-book stories about the Holocaust and interviews with some of the biggest names in the business.

“After the war, there were comic-book stories in regular publications that talked about the Holocaust when other people weren’t talking about it,” said Neal Adams, the enormously influential New York comics artist who created the book with Holocaust scholar Rafael Medoff and comics historian Craig Yoe.

“The comics industry is filled with Jews. Almost all of the artists and writers were Lower East Side kids who as teenagers got into comics,” he said.

“Comic people didn’t have too many shackles on them. You’d just say [to an editor], ‘I’d like to do a story on Rommel,’ ” he said, referring to Hitler’s field marshal Erwin Rommel, nicknamed “The Desert Fox.”

“We Spoke Out” features words and images from comics legends such as Stan Lee, former Mad magazine editor Harvey Kurtzman, “Daredevil” artist Wally Wood and “Sin City” writer/artist Frank Miller. It includes stories from both DC and Marvel.

“To get . . . DC and Marvel together on the same project shows what an important project this is,” says Yoe, an upstate resident whose IDW Publishing imprint, Yoe Books, released the hardcover collection.

The project grew out of Adams and Medoff’s own Holocaust comic.

The two men met while championing the cause of Dina Babbitt, an Auschwitz survivor who had been forced to paint portraits of gypsies by the Nazi doctor Josef Mengele.

In the 1970s, the museum at the former concentration camp contacted Babbitt — who had since moved to the US and married an animator — to say it had found her paintings. But the museum refused to let her take them home, and she spent the rest of her life campaigning for their return.

Adams and Medoff turned her story into a comic that ran in a 2008 issue of the miniseries “X-Men: Magneto — Testament,” which was set in Auschwitz and is the final chapter of “We Spoke Out.”

While working on the story, Medoff said, he recalled how he had learned about social issues such as racism and drug abuse from Adams’ work, especially his groundbreaking run with writer Denny O’Neil on the “Green Lantern” series in the 1970s.

“Reflecting on these comics Neal had illustrated to do with racism and these other issues got us thinking about whether comics had talked about the Holocaust during those years,” says Medoff, founding director of the David S. Wyman Institute for Holocaust Studies in Washington, DC.

“Whether comics might have been a source for young people to learn about genocide.”

They had.

Not only did Adams recall drawing several Holocaust-related comics himself, Medoff, a lifelong comics fan, was wowed by the other titles they turned up.

“I had expected we would find the stories in war comics. But I was surprised to find Holocaust themes in mainstream superhero comics like ‘Captain America,’ ‘Batman,’ ‘X-Men,’ ” Medoff says.

“It lends strength to the argument that this was something kids were reading about — these were the biggest titles, kids were reading this stuff.”

The pair spent several years combing through archives and chatting with experts to unearth forgotten gems and secure the rights to the best stories.

Among them was “Master Race,” a legendary 1955 comic written by Al Feldstein and drawn by EC Comics illustrator Bernie Krigstein that slowly reveals its narrator to be a former Nazi concentration camp commander living in New York.

“It’s considered by many as one of the high points of the art form. It’s just brilliant the way it’s told, very cinemagraphic, very innovative,” Yoe says.

Another of Adams’ contributions is a classic 1971 comic written by O’Neil in which the Dark Knight hunts for a Nazi war criminal at a Halloween party.

But other inclusions had almost been lost to the ages — including “Desert Fox,” a war comic published in 1951 just as some historians were trying to rehabilitate the image of Rommel and recast him as a great military leader with no real connection to the Nazi regime’s war crimes, according to Medoff.

“[It] takes Rommel’s reputation and shows in comic-strip form that he was not just a talented general but part and parcel of the Nazi movement,” Medoff says.

“These creators felt like they wanted to be part of a serious conversation, and they brought teenagers into this serious debate. As a historian, I was very impressed [by] their level of knowledge and determination to refute the revisionist historians.”

Medoff was also impressed to discover a 1969 Captain Marvel comic that paired the hero up with a Holocaust survivor as they tried to escape a mad sociologist experimenting on them “for the betterment of the race” — the first time a superhero story had directly discussed the Holocaust.

“I think many people will be surprised by the characters that are household names that were part of the stories,” Yoe says.

“The superheroes themselves are an incredible cast. Real and fictional characters coming together, making people aware of this important subject.”

“We Spoke Out” is hitting shelves just after a study revealed that many millennials remain ignorant about the Holocaust — with 66 percent not knowing what Auschwitz was and almost half believing that fewer than 2 million Jews were killed, when, in fact, up to 6 million were.

The authors hope their book will once again help comics-obsessed kids learn about this dark chapter of human history.

“For the average American teenager, it’s something that happened a long time ago to other people in a faraway land. There’s nothing like comic books to get teenagers interested,” Medoff says.