When Chadwick Boseman stepped into the Marvel Cinematic Universe for the first time for Marvel’s Captain America: Civil War in 2016, a fan asked him what he had in common with his character T’Challa. “I am a keeper of secrets and I think T’Challa is definitely a keeper of secrets,” he said in an “Ask Marvel” video. “That would be the one thing I’m going to say because everything else you don’t need to know.”

Flashing his trademark grin throughout the answer, there was no indication that the secret the South Carolina-born actor could be holding onto might be literally a matter of life and death.

But that same year, just as his already impressive career — having played Jackie Robinson in 2013’s 42 and James Brown in 2014’s Get On Up — was shooting to meteoritic heights, he learned that he had stage III colon cancer.

Instead of letting the diagnosis slow him down, Boseman pushed forth with even more zest, balancing the world of box office mega-hits with hospital treatments.

His secret finally came out when on August 28, 2020, when a post on his social media pages tragically announced: “It is with immeasurable grief that we confirm the passing of Chadwick Boseman.⁣”

At the age of 43, he had died in his Los Angeles home surround by his wife and family next to him.

He fought colon cancer for four years

The tweet, posted at 10:11 p.m., along with a matching Instagram, shocked the entire globe. From the outside, it had seemed as if Boseman was still a fresh face to Hollywood, the kind of breath of fresh air that the industry long needed for blazing a new path by playing historical Black American figures, as well as bringing diversity to the Marvel universe.

Instead, the statement also revealed one of the greatest secrets in Hollywood: “Chadwick was diagnosed with stage III colon cancer in 2016, and battled with it these last 4 years as it progressed to stage IV.”

Then it went on to reveal even more — that between all his starring roles, he had played the very real role of hospital patient. “A true fighter, Chadwick persevered through it all, and brought you many of the films you have come to love so much,” the statement continued. “From Marshall to Da 5 Bloods, August Wilson’s Ma Rainey’s Black Bottom and several more, all were filmed during and between countless surgeries and chemotherapy.”

Chadwick Boseman accepts the Best Performance in a Movie award for "Black Panther" at the 2018 MTV Movie And TV Awards at Barker Hangar in Santa Monica, California on June 16, 2018

Chadwick Boseman accepts the Best Performance in a Movie award for "Black Panther" at the 2018 MTV Movie And TV Awards on June 16, 2018

Boseman 'did not want to have people fuss over him'

The outpouring of support — from celebrities ranging from Oprah Winfrey to Joe Biden — was combined with all his fans trying to piece together how they could have missed something so life-threatening.

As it turned out, it was by design. In fact, it wasn’t meant to be a big secret — it was just the way Boseman was. “Chadwick did not want to have people fuss over him,” his longtime agent Greene & Associates Talent Agency’s Michael Greene told The Hollywood Reporter days after his passing. “He was a very private person.”

Greene was part of a very small circle who knew about Boseman’s dire health condition. The group also included his producing partner Logan Coles and his trainer Addison Henderson.

Henderson, who knew Boseman for nine years, prepared him for differing physical needs of his roles — from bulking up for Black Panther and then slimming down for Marshall in between. And Henderson knew how devastating cancer could be, watching his own father beat it four times. “I used to tell Chad, ‘Man, you remind me of my dad… You guys are fighters, and you never stop moving forward,” he told The Hollywood Reporter.

Though he was unaware of the diagnosis at the time, Dr. Wayne A.I. Frederick, the president of Boseman’s alma mater, Howard University, also recognized the same humble and selfless quality in the graduate. “One of his greatest attributes was never burdening anyone else, but being there to shoulder everyone else’s burdens,” he said.

He didn't let the disease control his life

The physical toll of such demanding roles mixed with such a painful diagnosis didn’t always mix well. “He was really in hard-core pain,” Greene said of Boseman’s time on the set of Ma Rainey’s Black Bottom. But he didn’t let that hold him back because he “felt that being able to be with [producer] Denzel [Washington] and to launch this cycle of August Wilson at Netflix was so exciting to him.”

Henderson also remembers how Boseman selflessly went out of his way to help him. After back-to-back shoots in Thailand for Da 5 Bloods followed reshoots for 21 Bridges, instead of going straight home, Boseman went to upstate New York to help Henderson, who was working on his own movie G.O.D.

“He was tired, but he came to Buffalo, where I shot my movie, and stayed for days with me, just to talk through stuff with me, just to be a good brother,” Henderson remembered. “He didn’t have to do that, he could have gone home and just rested. For me, that was just something that I’ll never forget.”

And that’s the spirit he admired most in his late friend. “Some people wait a lifetime to get the opportunity that he had and Chad had so much wisdom, so much knowledge, so much inside of him that he wasn’t going to let this disease stop him from telling these amazing stories and showing his art in the prime of his life,” he added.

Chadwick Boseman at the 90th Annual Academy Awards at Hollywood & Highland Center in Hollywood, California on March 4, 2018

Chadwick Boseman at the 90th Annual Academy Awards on March 4, 2018

Playing King T’Challa was the 'honor of his career'

It almost seemed as if Boseman just saw his cancer as a hiccup and kept plowing through life — or perhaps, it was knowing his time might be cut short that made him power through with his infectious grin. After all, it was after his 2016 diagnosis, that he filmed three more of the Marvel hits that he’s so remembered for, Black Panther and Avengers: Infinity War in 2018 and Avengers: Endgame in 2019.

In particular, stepping into the starring superhero role in Black Panther cemented his status as a trailblazer, as the film was called a “defining moment for Black America” by The New York Times.

The importance was not lost on Boseman, who said in his acceptance speech at the 2019 Screen Actors Guild Awards for Outstanding Performance By a Cast in a Motion Picture: “To be young, gifted and Black, we all know what it's like to be told that there is not a place for you to be featured. Yet, you are young, gifted and Black. We know what it's like to be told to say there is not a screen for you to be featured on, a stage for you to be featured on.”

"We know what it's like to be a tail and not the head,” he continued. “We know what it's like to be beneath and not above. And that is what we went to work with every day because we knew, not that we would be around during awards season and that it would make a billion dollars, but we knew that we had something special that we wanted to give the world. That we could be full human beings in the roles that we were playing. That we could create a world that exemplified a world that we wanted to see.”

And it’s because of Boseman that the world he spoke of came to be — and has become his legacy, as the Twitter announcement also said: “It was the honor of his career to bring King T’Challa to life in Black Panther.”