(Cristiano Siqueira for The Washington Post)

The Eagles are finished.

Don Henley is direct. The way he describes it, the group he helped lead since 1971 died with his longtime musical partner, Glenn Frey.

“I don’t see how we could go out and play without the guy who started the band,” says Henley.

He sits inside the Tudor mansion in Lincoln that serves as the headquarters for the Walden Woods Project. Henley founded the nonprofit organization in 1990 to protect the land that inspired 19th-century transcendentalist Henry David Thoreau. He flew here for this interview, a reminder of how he has always separated what is public — being in one of America’s most popular bands — from the private — his life as a husband and father in Texas.

This should have been a time to celebrate. On Sunday, the three surviving members of the final edition of the Eagles — Henley, guitarist Joe Walsh and bassist Timothy B. Schmit, all of them 69 — will receive Kennedy Center Honors. But Frey’s death in January, from complications brought on by years of battling rheumatoid arthritis and colitis, has cast a cloud over the proceedings. Cindy Frey will be given her late husband’s medallion.

The Kennedy Center actually chose the Eagles for the award last year, but the band deferred in hopes that Frey would get better.

They had no reason to expect otherwise. Frey had stoically managed his health for decades and, in the summer of 2015, the Eagles wrapped up a massive tour. Frey headed to Hawaii with his family. He got sick and flew home for treatment. The drugs that helped him manage the pain compromised his immune system, and Frey caught pneumonia. Doctors induced a coma from which he never recovered. He died Jan. 18 at the Columbia University Medical Center in New York. He was 67.

Jackson Browne and the Eagles perform a tribute to Glenn Frey during the 58th Grammy Awards on Feb. 15. (Mario Anzuoni/Reuters)

A month later, the Eagles gathered on stage to perform a tribute at the Grammy Awards. Jackson Browne stood in for Frey on “Take It Easy,” a song Browne co-wrote. That week, Henley, Walsh and Schmit also performed at a private memorial with several guest singers, including Glenn’s son, Deacon. That may be the last time they play together.

“It would just seem like greed or something,” says Henley. “It would seem like a desperate thing.”

The Eagles have battled critics, conventions and each other, but they’ve never seemed desperate. Over time, the band sold more than 150 million albums and filled arenas from Cleveland to China. They also reinvented themselves more than once. During their 1970s run, the Eagles became famous for not only the music — “Their Greatest Hits (1971-1975)” is the best-selling album of the 20th century in the United States — but also their notorious backstage parties, the self-described “third encore.” Fewer people saw the less glamorous side, the process that led to all those hits, peaking with 1976’s masterpiece, “Hotel California.” The Eagles did it through hard work and a stable of writers competing for limited space and by being unwilling to settle for a sloppy take when another run-through might bring perfection.

“When this band started, we said, ‘We want it all. Critical acclaim, artistic success and financial success,’ ” says Bernie Leadon, the group’s first guitarist, “It wasn’t like we want to make a pretty good album so our girlfriends like us. No, it was, ‘We want to be the best f---ing band there is.’ ”

The intensity of that quest took its toll.

In 1975, worn out from the road, Leadon dumped a beer over Frey’s head and quit. He later apologized and, nearly 40 years later, the band hired him to take part in the group’s “History of the Eagles” tour.

On the night of July 29, 2015, Leadon and Frey huddled together offstage in Bossier City, La., as the crowd cheered. They were waiting to return for a final encore. This would be the group’s last real gig. You wouldn’t know it from what Frey said next.

“He gave me a big, huge thanks for participating,” remembers Leadon. “Then he said, ‘It’s been really awesome to have you back out there. This is not the end.’ ”

California Gov. Edmund Brown Jr., right, and singer Linda Ronstadt, center, with members of the Eagles during a concert at the Capital Centre in Maryland in 1976. (Karin Vismara/AP)
From backup band to Winslow, Ariz.

They started out backing Linda Ronstadt. Frey, a long-haired Detroit kid raised on Motown, and Henley, a shy Texan who had studied English literature in college, took a $250-a-week gig supporting the barefoot country rock queen. After a few months, Frey asked Henley to form a band. Frey recruited Poco’s bassist, Randy Meisner, and Leadon, a masterful string player who had backed Gram Parsons in the Flying Burrito Brothers.

“Glenn was the driving force,” remembers John Boylan, Ronstadt’s longtime manager. “Ambitious and talented as hell and just driven. Henley, an intellectual, thinker, tremendous singer, and really good drummer. Randy was a solid bass player and a great high harmony singer and great lead singer, too. Bernie’s just a mensch, man. One of the great people in our business.”

The four founding Eagles came from different places — Texas, Michigan, Minnesota and Nebraska — but they shared a moment, in Southern California, when psychedelic rock gave way to rich harmonies and Hank Williams covers. The Troubadour club in Los Angeles served as their home turf, a stage famous for spotlighting Carole King, James Taylor, Joni Mitchell and Warren Zevon.

“Young people coming up in music pull against the existing norms,” says singer JD Souther, who helped write a slew of Eagles hits. “What we found in common is we could all afford an acoustic guitar, we could find a piano somewhere, and we could sit down and make music without a big rig and a lot of money going out. And it sounded pure.”

The Eagles weren’t the first to apply four-part harmonies to country rock or twangy pulls to their power chords. But Souther says there is a reason they stood out.

“None of those other bands had consistently the kind of material that the Eagles had,” he says. “And that came from hours and hours of work.”

It also came from capturing a feeling, no more so than in their first single, “Take It Easy.” The song emerged in 1971 when Browne, renting a room below Frey, found himself stuck on the second verse. Frey picked it up, turning “Take It Easy” into a joyous anthem of youthful searching. The song landed the country rock sound, already developed but rarely on the radio, on the charts. By inserting just a handful of key references, Frey crafted a blueprint you can trace straight to Jason Aldean. Today, a bronze statue of a mustached Frey stands on a corner in Winslow, Ariz., the town referenced in the hit.

“I guess it’s the moment in the song where Glenn puts himself in the street,” Browne says. “He jumped in and he wrote that second verse, and he got ‘Lord,’ ‘Ford,’ ‘girl’ and ‘bed’ into one line.”

The Eagles reunited for their “Hell Freezes Over” tour in 1994. (Doug Pizac/AP)

Glenn Frey, left, and Don Henley perform during a 1994 reunion show. (Doug Pizac/AP)
‘I’m gonna . . . kill you’

By the end of 1977, Leadon was gone, as was Meisner. Schmit arrived from Poco. Walsh, an explosive player known for destroying hotel rooms, and guitarist Don Felder, nicknamed “Fingers,” allowed the group to shift effortlessly from soft rock to the electric funk of “Life in the Fast Lane.” Now they just had to get along.

“I would say struggling is a good word,” Walsh says. “We were all struggling to keep doing what we were doing and more things were expected of us. I mean, one of the big things was how in the world are we going to top ‘Hotel California’?”

“The Long Run” took almost two years to finish. By then, drugs were flowing, and lyrics were not. And Felder found himself at odds with Frey and Henley, still smarting when they refused to let him sing lead on a song he had brought them, eventually recorded as “Victim of Love.”

The tensions could not be hidden. On a summer night in 1980, the Eagles played a concert for then-Sen. Alan Cranston (D-
Calif.). An argument between Frey and Felder spilled onto the stage, captured on tape and included in the surprisingly bare 2013 documentary “History of the Eagles.”

“I’m gonna f---in’ kill you,” Frey taunted Felder at one point. “I can’t wait.”

The Cranston gig marked the last time the Eagles would play together for 14 years.

“I always thought about the Rolling Stones when we were apart,” says Schmit. “I would see that the Stones were still together even though there was a lot of publicity about Mick and Keith having a lot of problems. That’s what it finally came down to. Let’s do this thing and come together and work again.”

After the Eagles, Frey traded in his jeans for white suits and had hits with “Smuggler’s Blues” and “The Heat is On.” Henley’s ’80s material was more melancholic, including “The Boys of Summer” and “The End of the Innocence.” When asked whether they might reunite, he would famously say “when hell freezes over.”

In 1990, manager Irving Azoff managed to get Henley to agree to a reunion, but Frey didn’t show for rehearsals. Three years later, he had better luck. Henley, Frey, Felder, Schmit and Walsh came together for a video shoot of Travis Tritt’s cover of “Take It Easy.”

“That’s the first time we had all been in a room together for a while, but I don’t think that precipitated the reunion,” Henley says. “I think enough time had gone by, and Irving had talked to everybody one on one. He realized that we were still a big deal, that we were still popular. We didn’t realize it, we didn’t really think about it.”

In 1994, the Eagles got back together for the “Hell Freezes Over” tour. They would continue to play live, even after firing Felder in 2001 — a dispute that led to lawsuits, resentment and the guitarist writing a tell-all memoir. Felder, who declined interview requests, urged fans on Facebook to sign a petition demanding the Eagles add him, Meisner and Leadon to the Kennedy Center Honors. That’s been discussed, but Azoff, in talks with Kennedy Center President Deborah Rutter, has said that only Frey, Henley, Schmit and Walsh should receive medallions.

We will never know how well the Eagles’ leaders got along in later years. Henley doesn’t go into great detail about their relationship. At one point during the interview at Walden, he spoke of the shift that occurs from working so intensely with one person.

“You know all their little tics and their eccentricities and their peccadillos and everything about them so well that they become predictable and you know their weak points and their strong points, and after a while it starts to grate on you,” he says.

Those who watched the pair have differing views of the dynamic.

“Quite frankly,” says Souther, “the thing we don’t hear often enough is that I think they really missed each other’s company and this thing they knew they could do probably better than just about anybody.”

Browne described Henley and Frey differently.

“I think that they figured out how to come back together and work, but I don’t think they ever quite achieved the same kind of bond that they had in their youth,” he says.

He recounts a telling exchange with Henley before the Grammy tribute.

“I mentioned, in retrospect, ‘You know, I was really estranged from Glenn,’ and he said, ‘I was, too.’ ”

From left, Timothy B. Schmit, Don Henley, Glenn Frey and Joe Walsh of the Eagles pose for a photo after a news conference in Park City, Utah in 2013. (Chris Pizzello/AP)
Taping up his hands like a football player

However they felt about each other, Frey and Henley did not re-form the Eagles to sloppily play though their old hits. Leadon discovered that when he rejoined the group for the “History” tour in 2013.

“We went through seven weeks of rehearsals before the tour, and then each day we did a sound check and a mini-rehearsal on things that Glenn thought needed to be gone over from a previous show,” Leadon says. “In addition, every show was recorded at the mixing console, and Glenn would often say, ‘I went in and listened to this and we need to go over the vocals on this particular song.’ ”

They were older now, long past late-night parties. Henley wouldn’t even go to dinner after a gig, preferring to retire to his hotel room to rest his voice. He brought a stationary recumbent bicycle with him on the road. He’s in good health but admits drumming has left him with tingling in one hand from nerve damage and a shotgun punch in his left ear whenever he whacks a snare.

Frey’s health problems were different. As far back as the 1980s, he had been forced to cancel gigs to deal with chronic intestinal problems. His rheumatoid arthritis grew worse over the years.

“He would have to tape his hands up like a football player,” says Henley. “I watched his hands, his fingers, became bigger and more gnarled and stiff. I knew what those fingers used to look like.”

Musician Glenn Frey in 1985. (Mario Suriani/AP)

Frey speaks at the 2014 Rock and Roll Hall of Fame induction ceremony. (Charles Sykes/Invision/AP)

“He was taking some really strong drugs to keep it under control,” Souther says, “but he’s tough. There’s a lot of courage and tenacity in this guy. He’s an absolutely ball-busting sergeant, and he demanded the same thing of himself.”

There was no talk of anything ending when the Eagles wrapped their “History” tour. Frey told his friend Bob Seger that he was working on a play. There was chatter about playing the entire “Hotel California” record live.

When Frey met his doctor in Los Angeles last year, he learned he had ulcerative colitis, Azoff says. Doctors talked to him about removing part or all of his intestine. Then his medication was changed. He got the pneumonia that would kill him.

“Powerful drugs suppress your immune system,” Azoff says. “I don’t think the family or I could say for sure that it was the years of having rheumatoid arthritis vs. the change in the drug that caused the pneumonia.”

The last time Henley saw Frey was in the hospital. He and his wife, Sharon, sat by Frey’s bed with his wife, Cindy. Frey was in a coma, and he didn’t regain consciousness. On the third Monday of January, he died.

At a large, private memorial service in February, Henley read a eulogy that took him almost a month to compose. In moving detail, he talked about their 45-year relationship.

Then the remaining Eagles played one of Frey’s signature songs, “Peaceful Easy Feeling.” Deacon Frey sang and strummed an acoustic guitar.

Henley, left, and Frey perform during the CMA Awards on Nov. 7, 2007. (Jeff Adkins/AP)

“Everybody was in complete shock,” says John Boylan. “Because he nailed it. And of course, everybody in the room said, ‘This could happen again.’ ”

Earlier this year, a reporter at the Montreal Gazette asked Henley if he imagined a future for the Eagles. He paused and then praised Deacon and referenced the idea of playing again with Browne. But he cautioned that “there have been no discussions along those lines, and we’re still going through the healing process — trying to get through all of this.”

Later, Billboard magazine referred to this interview with a headline that read: “Eagles could reunite, if Glenn Frey’s son agrees to join the band.”

“I didn’t realize that Billboard had become a tabloid,” Henley says, still annoyed. “It really pissed me off, frankly, because I hadn’t talked to the kid about it or his mother. So it’s just another lesson in keeping my mouth shut.”

Browne talked of what he heard at Frey’s memorial. He admits he wishes that Henley would reconsider.

“This is a great band even if it went on without Glenn,” he says. “They could have no trouble playing and singing those songs with guests. Like they had Bob Seger play at the memorial. They had me sing a song. They had JD Souther sing, and he’s an incredible singer these days. I didn’t say this to them because they all seem resolute in saying, ‘Well, that would be wrong,’ but I see how the band could go forward without Glenn.”

Azoff has heard these questions before. It took him 14 years to get the Eagles back together the first time. He’s asked whether he can imagine the band ever playing again.

“I think Henley was the guy that came up with the words ‘when hell freezes over,’” he says and pauses. “If hell can freeze over, pigs can fly. I’d never say never.”

The 39th Kennedy Center Honors ceremony will be held Dec. 4 at 7 p.m. in the Opera House. The taped presentation will be broadcast Dec. 27 at 9 p.m. on CBS.