References

Earlies evidence

2130 BCE – Earliest evidence of DMT usage in the form of entheogenic Yopo snuffs, derived from Anadenanthera seeds in NW Argentina.
Torres, C. M. 1996. “Archaeological Evidence for the Antiquity of Psychoactive Plant Use in the Central Andes.” Annali dei Musei Civici-Rovereto 11: 291-326.
Torres, C. M. 1998. “Psychoactive Substances in the Archaeology of Northern Chile and NW Argentina: A Comparative Review of the Evidence.” Chungará 30 (1): 49-63.
1931-DMT is first synthesized by Richard Manske.
Manske, R. (1931). A synthesis of the methyltryptamines and some derivatives. Canadian Journal of Research 5, 592-600.

3800 BCE – Earliest evidence of suspected Peyote cacti usage in North America.
El-Seedi HR, De Smet PA, Beck O, Possnert G, Bruhn JG. (2005) Prehistoric peyote use: Alkaloid analysis and radiocarbon dating of archaeological specimens of Lophophora from Texas. Journal of Ethnopharmacology 101(1-3):238-42
1897 – German chemist Arthur Heffter isolated Mescaline from Peyote.
Character Vaults, Erowid.org [online]

Little is known about its traditional use as an entheogen.
Sage Wisdom 1997 [online]
1938-Jean B. Jtohnson wrote about Salvia divinorum (Hierba Maria) in his publications about the Mazatec shamans.
Marushia, Robin (June 2003). “Salvia divinorum: The Botany, Ethnobotany, Biochemistry and Future of a Mexican Mint” (PDF). Ethnobotany.

1851 – “English botanist Richard Spruce encountered the use of an intoxicating beverage among Tukano Natives of the Rio Uapes in Brazil” this was the first non-published scientific discovery of Ayahuasca.
Metzner, R. (Ed.). (2005, p 44). Sacred vine of spirits: Ayahuasca. Inner Traditions/Bear & Co.

Over thousand scientific papers on psychedelics published, discussing around 40.000 patients; six international conferences on psychedelic drug therapy.
Grinspoon, L., & Bakalar, J. B. (1979). Psychedelic drugs reconsidered (pp. 221-223). New York: Basic Books.
Example: Dr. Oscar Janiger, a psychiatrist who conducted studies on the effects of LSD in Los Angeles from 1954 till 1962. He conducted experiments with 900 participants, asking them for their phenomenological experiences. The follow up analysis of the data from 45 participants suggests that LSD can be safely administered in controlled doses to healthy humans by researchers trained in psychotherapy. Doblin, R., Beck, J. E., Chapman, K., & Alioto, M. (1999). Dr. Oscar Janiger’s Pioneering LSD Research: A Forty Year Follow-up. Bulletin of the Multidisciplinary Association for Psychedelic Studies, 9, 7-21.
Expansion of the hippie movement, which promoted the use of psychedelic drugs such as marijuana and LSD as harmless and non-addictive ones, in order to explore the altered states of consciousness.
The Hippie Counter Culture Movement (1960’s)

All scientific psychedelic research on humans banned in U.S.
Fadiman, J., Grob, C., Bravo, G., Agar, A., & Walsh, R. (2003). Psychedelic research revisited. Journal of Transpersonal Psychology, 35(2), 111-126.
October 1966 – LSD was considered as having a negative impact on the values of the Western middle class and declared a controlled substance in California. The rest of the world followed. After that, the LSD black market emerged. United States. (1968). Increased controls over hallucinogens and other dangerous drugs: Hearings, Ninetieth Congress, second session, on H.R. 14096 … [and] H.R. 15355. Washington: U.S. Govt. Print. Off.
1967 – Summer of Love-San Francisco. Around 100,000 people gathered, influenced by the movement and lifestyle.
Selvin, J. (1994). Summer of love: the inside story of LSD, rock & roll, free love, and high times in the wild West. EP Dutton.
October 1970 – LSD was considered as having a negative impact on the values of the Western middle class and declared a controlled substance in California. The rest of the world followed. After that, the LSD black market emerged. End the Ban on Psychoactive Drug Research [online]
1986 – Second Summer of Love-Britain. A renaissance of acid house music and rave parties. Supported MDMA and LSD use. Reynolds, S. (1998). Energy Flash: A Journey Through Rave Culture and Dance Music. Picador, London.