Alex Horwitz, director of the documentary "Hamilton's America," at his parents’ home in Chevy Chase. (Matt McClain)

The first sight Alex Horwitz ever caught of Lin-Manuel Miranda was on a stage at Wesleyan University, playing the title role in — aptly enough, given the near-idolatry that would one day follow — “Jesus Christ Superstar.”

The two became buddies and then ­castmates in an extracurricular improv-
comedy troupe. “He was our fifth Beatle,” Horwitz jokes of his fellow member of the Class of 2002. Years later, as Miranda himself climbed toward superstardom, they would forge an even more significant alliance, for a project that would not only propel Horwitz’s trajectory as a filmmaker but also set down a definitive account of the means by which his college pal would change musical theater and, perhaps, American culture.

“Hamilton’s America,” the fruit of Horwitz’s three years of following the development — and spectacular success — of Miranda’s legend-in-its-own-time musical “Hamilton,” is unveiled for the world Friday night at 9 on PBS’s “Great Performances.” The eagerly anticipated documentary is not, however, just another backstage film about the arduous task of putting together a musical. The film takes a more ambitious tack, in its attempt to weave a portrait of both Alexander Hamilton, the Founding Father who is the show’s title character, and the Singing Composer who had the inspiration to turn history into a hip-hop Broadway musical.

“The film is three years of what his life was like, from the writing process to the awards and accolades,” says Horwitz, a Chevy Chase native who lives in New York with his wife and son, with another boy due any minute. “I didn’t have an agenda for how I wanted to present him, other than simply to make a record of this moment of his life.”

Augmented by interviews with a formidable A-list of politicians, academics, “Hamilton” cast members and American celebrities, “Hamilton’s America” is, as Horwitz advertises, a further elucidation of a pivotal historic figure through a singular artist’s eyes. Talks with the likes of President Obama, former president George W. Bush, Sen. Elizabeth Warren, House Speaker Paul D. Ryan and Broadway composer Stephen Sondheim round out the discussion of both Hamilton’s place in the pantheon and the finer points of making a Revolutionary hero sing.

Director Alex Horwitz follows the development and success of Lin-Manuel Miranda’s musical “Hamilton” and gives viewers more than than just a behind-the-scenes look at the play, telling the story of both composer and Founding Father. (PBS/Great Performances)

If “Hamilton” seeks to frame the nation’s first treasury secretary, the visionary who invented the nation’s monetary system, as a recognizably flawed human being, “Hamilton’s America” opens yet another window on Miranda, who comes across as appealingly down-to-earth, earnestly engaged with his world and, yes, a bit of a musical theater geek.

“Lin’s public persona is very much the same as his private persona — he’s a gregarious, quick-witted guy,” Horwitz says, adding that his subject made the filming fun and, despite the long hours and technical demands, never an exercise in pulling teeth: “I could always count on Lin to be a good showman,” he explains. “It’s no surprise that he has a very good sense of story. He knew what was compelling — and he’s good in front of a camera.”

Horwitz, whose father, Murray, is a playwright (“Ain’t Misbehavin’ ”) who was founding director of AFI Silver Theatre in Silver Spring, has pursued a film career as an editor and director, albeit one of some eclectic tastes: A few years ago he made a short movie, “Alice Jacobs Is Dead,” that he describes as a “zombie love story.” In the aftermath of the initial public excitement about Miranda’s Hamilton project, he approached his old friend about a documentary. Modeling his concept on “Looking for Richard,” a 1996 documentary that followed Al Pacino as he explored contemporary ideas about Shakespeare in researching the title role in “Richard III,” he pitched it to Miranda: “We could do a straight-up behind-the-scenes documentary, but I’ve seen that movie,” Horwitz told him. “The more interesting thing is to make a documentary about Alexander Hamilton.”

Miranda was on board for that and, soon enough, Horwitz was serving both as director and sound man, alongside cinematographer Bryant Fisher, filming Miranda as he wrote lyrics on his laptop in a bedroom in which Aaron Burr — who of course figures notoriously in Hamilton’s story — once slept. After filming began, RadicalMedia — where Horwitz has worked as a freelance editor and which produced a documentary about “In the Heights,” Miranda’s first Broadway musical — agreed to produce this one, too. PBS would sign on as well, and the production’s size and crew grew.

Horwitz envisioned the documentary as a mirror of “Hamilton”: presenting a story belonging to no single partisan or ideological identity. “This is a film about shared history, shared ideals,” he says. As a result, he felt it natural to invite commentators on Hamilton’s legacy from both sides of the aisle. Once he could get across the fact that this was an opportunity to expound on history, he found that politicians readily agreed to be in it.

“They were thrilled,” he said of people such as Warren and Obama, and George and Laura Bush. “They were like, ‘Oh, my God, I get to talk to somebody about what I’m excited about — I get to nerd out about history?’ All of them could not have been more welcoming.” (Off camera, one of the famous interviewees, who had not yet seen ‘Hamilton,’ asked him: “So is it really that good?”)

Viewers will probably be able to discern, even from the smattering of musical numbers that show up in “Hamilton’s America,” that indeed it is. Horwitz knows that it was the magnetic pull of the musical that provided him with the kind of access that does not occur every day for a film involving a world so distinct from the concerns of government.

Lin-Manuel Miranda, writing in Aaron Burr's bedroom at the Morris-Jumel Mansion in a scene from “Hamilton’s America.” (RadicalMedia)

“It is certainly a fact that ‘Hamilton’ got them to return the call,” he says. “The way I put it is, Lin opened the door. We just walked right through it.”

Hamilton’s America airs Friday at 9 p.m. on PBS’s “Great Performances.”