Julius Rosenwald was born in 1862, the son of an immigrant peddler, and rose to become part owner and president of Sears, Roebuck and Company, which he helped build into the largest retailer in the U.S. He was also a philanthropist. Along with various good works in Chicago, where he lived, he helped build more than 5,000 two-room schoolhouses in the South for African-Americans, which became known as “Rosenwald schools.” From 1917 to 1948, the Rosenwald Fund also made grants directly to African-American artists and researchers, including Langston Hughes, Jacob Lawrence, James Weldon Johnson, Augusta Savage, John Hope Franklin, Charles Drew, Gordon Parks, Jr., and James Baldwin. Rosenwald died in 1932.

Documentarian Aviva Kempner (“The Life and Times of Hank Greenberg,” “Yoo-Hoo, Mrs. Goldberg”) brings Rosenwald’s story to life in “Rosenwald,” which is playing this week at Sundance Cinemas in Seattle, with a special screening tonight, Friday, October 30, with Rosenwald’s grandson and biographer, Peter Ascoli, in attendance. There will be a Q&A with Mr. Ascoli after the 6:45 screening.

I spoke with Ms. Kempner on Monday.

After viewing your documentary, and hearing Julius Rosenwald’s story, I was amazed—and a little chagrined—that I’d never heard of him. How did you come across him?

I was lucky enough, 12 years ago, to attend a lecture by Julian Bond about blacks and Jews. I thought it was going to be about the Civil Rights era, but Julian surprised me by talking so eloquently about Julius Rosenwald and the schools, and how his own father and his uncle had gotten money from the Rosenwald fund. So I decided that had to be my next film.

It fit in with my M.O. about doing films about under-known Jewish heroes. I suspect he is the most under-known. It also fit ... In all my films, my protagonist is fighting an ism: Hank Greenberg was fighting anti-Semitism and Fascism, Molly Goldberg was fighting sexism and McCarthyism, and with this film, obviously, Rosenwald was fighting racism.

Early in the doc, one of your talking heads, Lester Mae Hill, who attended a Rosenwald school, asks, “What was his interest in doing this for the African-American community?”

Isn’t Lester wonderful? She was just so amazed, coming from the Jim Crow South, why a white man would want to do it.

I know your documentary is an extended answer to that question, but what’s the short answer?

I think we answered it several ways. Reading Booker T. Washington’s Up From Slavery, [Rosenwald] realized what a profound problem there was in the South in terms of literally keeping African-Americans in the field and not affording them a good and equal education. Second, his Rabbi had taught him the tenets of Tikkun olam: “Repairing the world.” And I think growing up under the corner shadow of Abraham Lincoln’s home, he was inspired. He really operated on the philosophy, “Give while you live.”

So why do you think Rosenwald’s story, which is an amazing American story, is not better known?

I think it’s a combination of things. It was over 100 years ago; he was such a modest man; and it was in the South and the Midwest. So the people who went to the schools remember it, and people in Chicago certainly knew who he was. But I can’t tell you how many people ... Just the other day, someone in my audience said, “I grew up in Chicago: How did I not know this story?”

Exactly. In some ways he’s the bridge between Plessy v. Ferguson and Brown v. Board of Education.

Well, it’s interesting because some of this [archive] footage was shot by Charles Hamilton Houston. He was the mentor to Thurgood Marshall.

Did Rosenwald ever get criticized for helping educate black people?

Eugene Talmadge, the governor of Georgia, really called him out on it. That’ll probably be in the DVD. And I think burning down the schools is criticizing, don’t you?

When you began your research, what did you discover that surprised you most?

Going in, I thought it was just the schools. Then I heard about the fund. Even more surprising is the fact that so many of the young people who work for me, black and white, don’t know who Marian Anderson is, and how important her story is. I’ve had an older white woman at one of my screenings come up to me and say, “I learned more about African-American history watching this film than I ever learned in all the years at school, including college.”

Rosenwald also did a lot with Jewish charities in Chicago. Why not include more about that in the documentary?

Well, what can you do? I think that’s more what you would expect him to do, and I really wanted the film to be how he rose beyond what you would expect: How a successful Jewish businessman in a major, very northern city [helped African-Americans in the South]. And I had the people that were really affected by it.

I could do a whole other film of what isn’t in the film. He was also on the crime commission—this was the time of Al Capone. There was a horrible [race] riot in 1919 and he was on the commission to study that. He and the mayor of Chicago prevented Birth of a Nation from being shown in Chicago for a while.

In your documentaries, you do something I haven’t seen many other filmmakers do: You use feature-film footage to illustrate some part of the story that doesn’t have footage—as when Rosenwald’s father is peddling in Virginia in the 1850s and you show a clip of Gene Wilder in “The Frisco Kid.”

I think these scriptwriters oftentimes get it really right. It’s proven when [historian] Hasia Diner says, you know, “The peddler would sell to the immigrant, the African American, the Indian,” and I remembered an episode of “Dr. Quinn, Medicine Woman,” and it was exactly in that order.

You also have Clint Eastwood in an old episode of “Rawhide” being taught the word “schlamazel” by a Jewish peddler. Nice find. Where did you get that?

The Paley Center for TV and Film. You just spend the time researching. Almost every cowboy series had a peddler. Probably because there were a lot of Jewish screenwriters.

There’s a great lesson for rich people today, too, particularly those running for office. [In the documentary Rosenwald says the following: “Don’t be fooled by believing that because a man is rich he is necessarily smart. There is ample proof to the contrary. Most large fortunes are made by men of mediocre ability, who fumbled into a lucky opportunity and couldn’t help but get rich.”]

Oh, I’d say it’s the best [antidote] to Trump’s line.

So which under-known Jewish hero is next?

Whoever I really can fall in love with. And I can get the money up front.

But who would be ideal?

I like the idea of [MLB catcher and OSS spy] Moe Berg. Go back to a little baseball.