The band formed in Los Angeles in August 1966 from the folk rock group The Ashes, which included John Merrill (guitar/vocals), Barbara "Sandi" Robison (vocals), Alan Brackett (bass/vocals), Spencer Dryden (drums), and Jim Cherniss (guitar/vocals).

Alan Brackett hooked up with a new guitarist, Lance Baker Fent, and a new drummer, Jim Voigt, naming the new trio The Crossing Guards.

[1] It was also produced by Usher, who brought in studio musicians including Glen Campbell and James Burton to bolster the group's sound.

[3][4] In 1968, they moved to the Warner Bros. Records subsidiary label Challenge with a revamped line-up featuring ex-Clear Light organist Ralph Schuckett and drummer Michael Ney (Stevens).

Brackett also produced, wrote and performed songs for scores of movies and television shows including Witness, Happy Days, and Top Gun.

In September 1971, Robison, Merrill, and Brackett joined a band called Froggy, which worked in a local saloon in Pasadena, California.

Robison fell ill while performing in Butte, Montana, and died of toxic shock poisoning 16 days later, on April 22, 1988, in a hospital in Billings, at the age of 42.

The three surviving members of The Peanut Butter Conspiracy performed Brackett's song "Eventually" at Amoeba Records on September 22, 2009.

Singer Karen Mitchell and drummer Jim Laspesa joined original members Brackett, Merrill and Fent in the re-formation of The Peanut Butter Conspiracy.

[8] According to Brackett: "I got together upon John's recommendation with Fent and Voigt and, with the help of Owsley, we learned 50 or so songs in one day and went out that night and got our choice of about three gigs in Hollywood.