[3] It was widely lauded for its up-close and uncompromising look at the Hells Angels motorcycle club, during a time when the gang was highly feared and accused of numerous criminal activities.

[citation needed] In March 1965, The Nation editor Carey McWilliams wrote to Thompson and offered to pay the journalist for an article on the subject of motorcycle gangs, and the Hells Angels in particular.

[citation needed] Thompson spent the next year preparing for the new book in close quarters with the Hells Angels, in particular the San Francisco and Oakland chapters of the club and their president Ralph "Sonny" Barger.

Far from being wary of this outsider, the Angels were sincere in their participation, often talking at length into Thompson's tape recorder and reviewing early drafts of the article to ensure he had his facts straight.

[10] In a contemporary New York Times review of the book, Thompson relates how he "drank at their bars, exchanged home visits, recorded their brutalities, viewed their sexual caprices, became converted to their motorcycle mystique, and was so intrigued, as he puts it, that 'I was no longer sure whether I was doing research on the Hell's Angels or being slowly absorbed by them.'

Reviews of the work were generally very positive and despite a poor performance on the publicity tour by Thompson, who was by his own admission drunk or exhausted for nearly every interview, the book sold relatively well.