The 82-year-old founder of Garth Fagan Dance, a company that includes dancers ranging in age from their teens to their early 70s, shared the secret to a successful multigenerational troupe: not just physical toughness, but also spiritual and intellectual wellness.

“You get youngsters with all their bounce and carrying on, and adults who are just making it work with great difficulty,” Fagan said.

Fagan, a Jamaican-born choreographer known for threading ballet training and discipline into his Afro-Caribbean movement, is also the longest-running Black choreographer in Broadway history because of his work on “The Lion King.” His choreography for that musical won a Tony Award in 1998.

His expansive work captured the attention of the Library of Congress, which announced this week that it had acquired a collection documenting Fagan’s legacy, including early photos of him as a teenage dancer and full visual recordings of works like “From Before” and “Prelude.”

The collection includes more than 30 years’ worth of footage of Fagan’s creative process with dancers, along with handwritten rehearsal notes, programs, posters, letters and audio recordings.

The library already holds collections of works by dance luminaries including Martha Graham, Erick Hawkins, Bob Fosse and Alvin Ailey.

Fagan’s choreography for “The Lion King” has been seen across the world, with the musical having been performed on every continent but Antarctica, producing nearly $10 billion in revenue. At the library, the archive includes souvenir programs, playbills and posters from “The Lion King.”

“I’ve seen it and rehearsed it all over the world in different languages, cultures and I get the same thrill every place I go,” Fagan said.

When his dance company, which was founded in 1970, returned to the Joyce Theater in November to perform six works, Gia Kourlas, the New York Times’s dance critic, called Fagan’s techniques “impossible until you see them with your own eyes.”

Fagan explained that his choreography requires dancers to build full-body strength, with an emphasis on the lower back. William Ferguson, the company’s executive director, once performed a work, “Dance Collage for Romie,” using crutches.

“One of the things that really inspired me to work to get our archive at the Library of Congress: the opportunity for the technique to be preserved in perpetuity,” Ferguson said.

Libby Smigel, a dance curator at the Library of Congress, said that after half a century of running a contemporary dance company, Fagan was finally getting the recognition he deserved.

“What we really don’t have is this hybridization of traditional forms with the classical ballet training, which now can train artists like racehorses,” Smigel said.

Most dancers retire at age 40, but Smigel said she admired the strength training and undulating movement synonymous with Fagan’s choreography that keeps the dancers’ muscles limber well into their later years.

“I wish I had been doing it all this time,” she said.