After honing their harmonies and polishing their country-rock grooves for half a decade, the Eagles scored a career-defining smash with 1976's Hotel California – and then spent the better part of the next three years trying to figure out how to follow it.

"I suppose we'd eventually finish some songs if we didn't have the pressure, but up to now it's been that way," Don Henley admitted in a 1977 interview. "I remember an interview I read a long time ago where [John] Lennon and [Paul] McCartney said that the only way they ever finished anything was to have a deadline, some kind of pressure."

But the pressure of following up a chart-topping, Grammy-winning, multiplatinum-selling record like Hotel California – an album whose protracted recording process and subsequent tour had already frayed the bonds between band members – proved to have the opposite effect on Henley and his fellow Eagles during the lengthy sessions for their next full-length effort, The Long Run. They entered the studio in 1977 to start working on what they initially envisioned as a double album, but the results didn't arrive in stores until Sept. 24, 1979.

And it wasn't a double album either. Worn out from years of constant recording and touring and unsure of how to build on Hotel California, the Eagles found it difficult to come up with songs they could stand behind – a significant development, considering that Henley, Glenn Frey, Don Felder, Joe Walsh and Timothy B. Schmit were all songwriters.

It took help from occasional co-writers like longtime friend J.D. Souther and Frey's fellow Detroit native Bob Seger, but they finally managed to polish off a 10-song LP.

"It made us very paranoid," Walsh later recalled of the years after Hotel California. "People started asking us, 'What are you going to do now?' and we didn't know. We ended up on the next album in Miami with the tapes running, but nobody knowing what was going on. We lost perspective. We just kinda sat around in a daze for ... months."

Listen to the Eagles Perform 'The Long Run'

Frey said everything changed for him during this period. "There was so much pressure that Don and I didn't have time to enjoy our friendship," he remembered. "We always had to worry about doing this or living up to that. We could talk about girls or football for a while, but it wouldn't be long before we'd remember that we had to make a decision about this – or that we had to get another song written for the next album."

It turned into a very public struggle to find a balance between outsized success and remaining true to their roots. "You can get out," Henley added. "The problem is getting out without getting completely out – without losing touch with everything. You have to work out a happy medium to keep your health and your wits about you. It can be done."

Perhaps. But the Eagles found it difficult to do it consistently with The Long Run, which nestled flashes of the band's old sound among less-inspired efforts, and buried the whole thing under a distressing amount of late '70s rock studio gloss. The group had never exactly been known for rocking out with wild abandon, but The Long Run sounded awfully mannered even in the context of their more-polished recent work.

Reviews were generally lukewarm and, on the whole, it was seen as something of a comedown after years of steadily growing sales.

Of course, that doesn't mean the album was a flop. Far from it. Although Led Zeppelin's In Through the Out Door kept it out of the top spot during its debut week, The Long Run rose to No. 1 in its second week – ultimately winning a Grammy, selling more than seven million copies and spawning three hits: the title track and "I Can't Tell You Why," both of which peaked at No. 8, and "Heartache Tonight," which would top Billboard's Hot 100 in November 1979 and prove to be the Eagles' final No. 1 single.

Listen to the Eagles Perform 'I Can't Tell You Why'

The band's audience was still eager for new music, but members of the Eagles continued to drift apart. Things grew particularly fractious between Glenn Frey and Don Felder, and by the end of the tour for The Long Run, it was all the two could do to share a stage with one another. As both men later remembered, their July 1980 stop in Long Beach, Calif., was marked with between-song threats of physical violence on both sides. It wasn't long before Frey decided he'd had enough of being an Eagle.

Glenn Frey might have been the first out the door, but he was far from alone in realizing the Eagles had run their course. Unfortunately, they still owed their label another album. The group quickly fulfilled their contract with the double-disc Eagles Live in November 1980, but like everything else between the band members at the time, it was difficult.

As producer Bill Szymczyk subsequently admitted, Frey's refusal to join them for overdubs – or even speak to his former bandmates – meant they had to take a piecemeal approach. "I had my assistant in Los Angeles with Glenn, and I had the rest of the band fly to Miami," he recalled. "We were fixing three-part harmonies courtesy of Federal Express."

So badly did the Eagles want to close the door on their collaboration that they ended up refusing to record new material for Eagles Live, despite being offered $2 million for a pair of songs. Even for a band as famously tumultuous as this one, it seemed like the end.

"We all came out here from different places, developed our talent, saw what it took to succeed and got the job done better than any of us ever imagined. At that point it ended, and life goes on," Frey once shrugged. "We always vowed to quit when we were still on top and that's what we did."

Listen to the Eagles Perform 'Heartache Tonight'

Henley would come to agree. "I'm very proud of what we did. We put everything we had into it at the expense of our health, friendships and everything else. But Glenn was right. It was time for it to end," he later admitted. "I have no regrets. I wish everyone else in the group well. There are some painful memories, but I'm beginning now to be able to look back and laugh a little."

For manager Irvin Azoff, the end seemed almost preordained. "The Eagles talked about breaking up from the day I met them," he said with a sigh in 1982. "There'd be one mini-explosion followed by a replacement in the band, then another mini-explosion followed by another replacement. You just had to step back and give things time to calm down.

"In my opinion, they broke up when Glenn and Don realized that they could both make great solo albums, and that's now," Azoff added. "They realized they don't need the Eagles anymore. That's why you're not going to see them go out and do a farewell tour or a farewell album or a farewell anything. It's just over, period."

For a long time, Azoff's pronouncement rang true, despite his continued efforts to secure a reunion-sized payday for his former clients. All the ex-Eagles embarked on solo careers, to varying degrees of success, and by the end of the '80s, neither Don Henley nor Glenn Frey seemed likely to want or need to submit to band politics ever again.

Everything changed in late 1993, when Azoff put together an Eagles country tribute album via his own Giant Records imprint – but that's another story.

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