The Harvard Psychedelic Club by Don Lattin is a fascinating look at how three Harvard University professors, and a graduate student came together in the early sixties to turn the world onto mushrooms, mescaline, and LSD-25.
For Timothy Leary, the journey began on the afternoon of August 9th, 1960, when he ingested some psilocybin mushrooms. That trip changed his perception of reality and convinced him psychedelic drugs would soon become an essential tool in the psychologist's toolbox.
Huston Smith had literally written the book on world religions, The Religions of Man, later republished as The World's Religions. He was introduced to Timothy Leary by Aldous Huxley, another Harvard Man, who'd written The Doors of Perception, a book based on his experiments with mescaline. Leary introduced Smith to his "magic mushrooms" on New Year's Day in 1961. It was a bad trip, but it opened him up to the possibilities of what Huxley called these "heaven and hell" drugs.
Richard Alpert was late to the party. By the time he arrived in Mexico, the "magic mushrooms" were gone, and no one knew how to find more, so he had to wait for his conversion. He took his first "trip" in early February of 1961.