When Robert Plant told the crowd "It feels great to be back” as Led Zeppelin played the second Oakland concert of their first U.S. tour in two years, he couldn’t have known it would also be their final show in America.

It was July 24, 1977, and there were just seven more concerts left on the schedule for the massive four-month tour, which kicked off on April 1 in Dallas. But when the singer’s 5-year old son died two days later, they were canceled.

On Sept. 11, 1980, the band announced plans for a return to the U.S. with a tour called the 1980s: Part One. But two weeks later, the day after the group's first rehearsal for that trip, drummer John Bonham died after reportedly drinking "40 measures of vodka in 12 hours." Two months later, Led Zeppelin said they wouldn't carry on without him, meaning that the British icons delivered their American farewell without knowing it.

Their 11th visit to the States had already been mired in conflict, partly caused by the loss of momentum forced upon them by Plant’s 1975 car crash. The 1977 tour was originally scheduled to start in February, but was postponed when the singer suffered an attack of laryngitis.

Tour logistics meant that their equipment had been shipped before the month’s worth of shows were called off, leaving guitarist Jimmy Page in a state of fear. In Led Zeppelin: Celebration II: The 'Tight but Loose' Files he said, “We didn’t have any instruments for a month. I didn’t play a guitar for a month. I was terrified at the prospect of the first few shows.”

Page – along with many others in the band’s entourage – was enduring a heroin addiction at the time, leaving some fans disappointed with his performances. Two shows had been overshadowed by riots, and longstanding band staff spoke of “darkness” behind the scenes, caused in part by drugs and in part by the hiring of London heavy John Bindon as security chief. The night before what was to be their final U.S. gig, Bindon, Bonham, manager Peter Grant and tour manager Richard Cole had been arrested after one of promoter Bill Graham’s crew was assaulted. Their second appearance at the Day on the Green festival at Oakland-Alameda County Coliseum had come close to never happening. Only Graham’s legal wrangling allowed the event to move forward.

As Led Zeppelin shows go, it’s reported to have been a good one, with the Oakland Tribune noting, “The musical highlight came during the extended jams – Page coaxing eerie sounds out of his axe using an array of electronic devices, and at one point using a violin bow on his strings; John Bonham rifling popgun drum rolls; bassist John Paul Jones looking unperturbed and confident behind the overt sexuality of Plant’s pelvic thrusts.”

Band members were less convinced. “That wild energy that was there in the beginning had come to the point where we were showboating a bit," Plant told Uncut in 2003. "We became victims of our own success. The whole deal about the goldfish bowl and living in it, that kicked in.”

After the show, Plant  received news that his son Karac had died of a stomach virus. The tragedy pulled the plug on what had been a profitable but unbalanced tour – and came close to ending the devastated father’s musical career. He later told Rolling Stone, “I lost my boy. I didn’t want to be in Led Zeppelin. I wanted to be with my family.” In another interview, he told Rock's Back Pages that he "wanted to just get out of it – to go away and forget it.”

Although Led Zeppelin eventually regrouped, the 1977 tour was a disappointing end to their American dream. While it was entirely normal for British bands that had joined the rock revolution early to be fascinated with the U.S., it would be safe to describe Zep’s interest as obsession.

“I wanted to find America in all its different colors and horizons – that’s been my trip," Plant told The Telegraph in 2013. "I never inhaled a chemical after 1977, but I’m still inhaling America. Robert Johnson stole my heart when I was 14.”

Raving about the blues music that fueled Zeppelin’s output and his later solo work, Plant noted that “it’s ridiculous that British musicians should have been able to get anywhere near it, because it’s based in African scales that don’t have any grounding on these islands. We were just moved by the color of the music. The sound was so evocative and poignant, something we were probably needing in our composite makeup – filling up a hole, an emotional outlet.”

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