Ms. Lacy, 68, recently allowed the tables to be turned, sitting for an interview in the sunny Manhattan offices of her company, Pentimento Productions, in the Starrett Lehigh building overlooking the Hudson River. It’s where she’s been based since she left WNET in 2013, and where she and a small staff have worked on the films she has made for HBO: “Spielberg,” a completed Jane Fonda biography and a work in progress about Ralph Lauren.
“I’m not going to pretend I didn’t have a little bit of postpartum,” she said, looking back at her 35-year tenure in public television. “Every couple of months it was like, ‘Unh unh unh’” — she made a crying noise — “and then it was like, ‘Oh my God, thank God I don’t have to raise money anymore.’”
Ms. Lacy grew up in Baltimore, the daughter of German immigrants who instilled a love of music that would be reflected in her “American Masters” films about artists like Leonard Bernstein and Joni Mitchell. After earning a master’s degree in American studies from George Washington University, she did short stints at both National Endowments (humanities and arts) and spent four years throwing dinner parties as the young wife of the head of the American Academy in Rome. A friend who was leaving a job at WNET suggested the station recruit her.
She returned to New York and took a job in program development, which she thought meant developing programs but which really meant raising money. She moved on to the arts series “Great Performances” and helped develop the drama series “American Playhouse.” Then she came up with the show that would be her life for the next three decades.
“I’ve always been interested, and had been since I was little, in reading biographies,” she says. “I wanted to read about Ernest Hemingway. I wanted to read about Picasso. I wanted to know those stories, and there was literally no place for it on television. I had this idea. I was going to focus on Americans, American cultural genius, and create a library of American cultural history of the 20th century.”
The rest is history, or in this case, biography. The show, with Ms. Lacy as executive producer, became a PBS institution.
But there were always hurdles. Complaints that her choice of subjects was too esoteric led to her first project as a director, the suitably populist “Paul Simon: Born at the Right Time” (directed with Susan Steinberg) in 1993. She came under increasing pressure to limit films to an hour in length.
And always, there was the ask. She spent an enormous amount of time finding money — from PBS, government agencies, corporations, foundations, wealthy individuals, DVD presales, foreign rights and co-productions.
That got easier over the years. Early “American Masters” budgets, she said, were around $750,000 a film. When Mr. Scorsese made his six-hour Bob Dylan documentary, “No Direction Home,” for the series in 2005, she was able to raise nearly $6 million.
But when Richard Plepler, chairman of HBO, asked Ms. Lacy to lunch in 2012, she realized she was ready to do things a different way.
“He said, ‘Would you leave?,’” she recalled. “I said, ‘I don’t know. It’s my heart, my blood, sweat and tears every single day.’ And he said the cleverest thing ever. He said, ‘Aren’t you tired of raising money?’”
Mr. Plepler remembers telling her: “‘It’s a waste of bandwidth. You’re a great filmmaker. I can alleviate that burden from you.’”
Her switch to HBO has meant working with another formidable figure, Sheila Nevins, the president of HBO Documentary Films.
“You could say I was startled,” Ms. Nevins said of the news of Ms. Lacy’s deal. “But then I looked back over the things Susan had done that I had relished — the Cole Porter, the Leonard Bernstein. And I think that I thought she added to the mix something that possibly I could not offer. So I sat back, and it turned out to be true.”
Ms. Lacy brought HBO not just her experience and talent but also a verbal agreement from Mr. Spielberg to cooperate with her on a film, wherever it ended up. They had met when she interviewed him for her last “American Masters” directorial effort, the 2012 “Inventing David Geffen.”
Over the course of two years and more than 100 interviews, 14 of them with Mr. Spielberg, Ms. Lacy constructed a film that combines copious footage from his movies with a quietly introspective consideration of the effects on him of his suburban upbringing and his parents’ divorce.
“My biggest thing is that I think Steven is a really personal filmmaker, and I think he’s not thought of as a personal filmmaker,” she said. “He’s not put in that category of somebody who’s bringing his soul to these films. I think there’s part of Steven in every film that he’s ever made, and that’s the story I wanted to tell.”
So does “Spielberg” capture Spielberg?
“I could not imagine being the subject of another filmmaker until I met Susan Lacy,” Mr. Spielberg, who has seen the film, said recently by email. “She engaged in a way that was so honest and insightful that it disarmed me and I discovered I could fall easily into any conversation with her, even about myself.”