Cannabis
One of humanity's oldest cultivated plants — sacred herb, folk medicine, banned narcotic, and now, increasingly, a legal drug. The 5,000-year story of cannabis.
Events
- c. 2800 BCEPeer-reviewedWell documented
Cannabis in Ancient China
Cannabis is one of humanity's oldest crops. In ancient China it was grown for hemp fiber and seeds, and it appears in early Chinese medicine — tradition credits the legendary emperor Shen Nung with recording its healing uses thousands of years ago.
Why it matters: China is one of the earliest homes of cannabis cultivation, where the plant was valued as fiber, food and medicine long before it spread across the world.
SourcesRelated timelines- History of China → — Among China's oldest cultivated plants
- c. 1500 BCEPeer-reviewedWell documented
A Sacred Plant of Ancient India
In ancient India, cannabis (bhang) was woven into religion and medicine. The Atharvaveda names it among sacred plants said to release anxiety, and it became linked with the god Shiva and used in Ayurvedic remedies.
Why it matters: India gave cannabis a lasting spiritual and medicinal role that endures today — one of the deepest cultural roots of the plant anywhere in the world.
- c. 500 BCEPeer-reviewedWell documented
Ritual Cannabis in the Pamirs
At the Jirzankal cemetery high in the Pamir Mountains, archaeologists found wooden braziers holding burnt stones and cannabis residue rich in psychoactive compounds — burned during funerary rites around 2,500 years ago.
Why it matters: It is the earliest clear chemical evidence for smoking cannabis for its psychoactive effects, showing the plant was used to alter the mind in ritual millennia ago.
- c. 450 BCEPeer-reviewedWell documented
The Scythians and Herodotus
The Greek historian Herodotus described the Scythians — nomads of the Eurasian steppe — throwing cannabis onto hot stones inside tents and 'howling with joy' at the vapor. Archaeology has since confirmed cannabis among Scythian burial goods.
Why it matters: It is one of the oldest written accounts of recreational and ritual cannabis use, from a culture that helped carry the plant across Eurasia.
- c. 1000–1300 CEPeer-reviewedWell documented
Hashish and the Islamic World
As alcohol was forbidden in Islam, hashish — concentrated cannabis resin — spread through the medieval Islamic world, from Persia to Egypt. It appears in poetry, medicine and folklore, and its use provoked recurring debate and attempts at prohibition.
Why it matters: The word 'hashish' entered global vocabulary here, and this era carried cannabis westward toward Europe and Africa.
- 17th–18th centuriesReputable sourceWell documented
Hemp in Colonial America
Cannabis also crossed the Atlantic as industrial hemp, grown across the colonies for rope, sailcloth and thread. George Washington cultivated hemp at Mount Vernon, once weighing whether it might beat tobacco as a cash crop.
Why it matters: Industrial hemp is the same species as marijuana but bred for very low THC — a reminder that 'cannabis' has always meant both a vital fiber crop and a psychoactive drug.
SourcesRelated timelines- American History → — Hemp among the colonies' fiber crops
- 1839Peer-reviewed · 2 sourcesWell documented
O'Shaughnessy Brings Cannabis to Western Medicine
The Irish physician William Brooke O'Shaughnessy, working in Calcutta, studied Indian cannabis medicine and in 1839 introduced it to Western medicine, testing extracts on conditions from rheumatism to convulsions and cholera.
Why it matters: His work triggered a wave of Western interest: over the following decades cannabis tinctures became common remedies in Europe and America.
SourcesRelated timelines- Medicine → — Cannabis enters the Western pharmacopoeia
- 1937Peer-reviewed · 2 sourcesWell documented
The Marihuana Tax Act and 'Reefer Madness'
In the 1930s, Harry Anslinger of the Federal Bureau of Narcotics led a sensational campaign against 'marihuana,' steeped in racial fear-mongering against Mexican and Black Americans. It culminated in the 1937 Marihuana Tax Act, which effectively criminalized cannabis in the United States.
Why it matters: This era, epitomized by the propaganda film Reefer Madness, entrenched the prohibition and racial stigma that would shape cannabis policy for generations.
SourcesRelated timelines- The Civil Rights Movement → — Prohibition built on racial fear-mongering
- 1961Peer-reviewedWell documented
The Single Convention on Narcotic Drugs
The 1961 UN Single Convention on Narcotic Drugs consolidated global drug treaties and placed cannabis among the most tightly controlled substances, committing signatory nations to prohibit its non-medical use.
Why it matters: It globalized cannabis prohibition, binding most of the world into a single restrictive framework that still shapes drug law today.
- 1964Peer-reviewedWell documented
THC Isolated: The Science Begins
In 1964, Israeli chemists Raphael Mechoulam and Yechiel Gaoni isolated and determined the structure of THC (delta-9-tetrahydrocannabinol) — the compound responsible for cannabis's psychoactive effects.
Why it matters: It launched the modern science of cannabis, eventually leading to the discovery of the body's own endocannabinoid system.
SourcesRelated timelines- Medicine → — The molecule behind the high
- 1970Peer-reviewed · 2 sourcesWell documented
The Controlled Substances Act and the War on Drugs
The 1970 U.S. Controlled Substances Act classified marijuana as Schedule I — the strictest category, defined as having high abuse potential and no accepted medical use, alongside heroin and LSD. Soon after, President Nixon declared a 'War on Drugs.'
Why it matters: Schedule I status made cannabis research nearly impossible and drove decades of arrests, fueling debates over drug policy and mass incarceration that continue today.
- 1992Peer-reviewedWell documented
The Endocannabinoid System Discovered
Following Mechoulam's work, researchers found that the human body makes its own cannabis-like chemicals. In 1992 they identified anandamide — the first 'endocannabinoid' — revealing a whole signaling system that regulates mood, appetite, pain and memory.
Why it matters: The discovery showed cannabis works by hijacking a natural system in our own bodies, transforming the scientific and medical case for the plant.
SourcesRelated timelines- Medicine → — The body's own cannabinoid system
- November 1996Reputable sourceWell documented
California's Prop 215: First Medical Cannabis
In 1996, California voters passed Proposition 215, the Compassionate Use Act — the first U.S. state law allowing patients to use cannabis with a doctor's recommendation, for conditions from cancer and AIDS to chronic pain.
Why it matters: It reopened cannabis as legal medicine in America and set off a state-by-state movement that would eventually challenge federal prohibition itself.
- November 2012Peer-reviewedWell documented
Colorado and Washington Legalize
In 2012, voters in Colorado and Washington approved ballot measures legalizing recreational cannabis for adults over 21 — the first U.S. jurisdictions to replace prohibition with a legal, taxed and regulated market.
Why it matters: They pioneered the modern legal-cannabis industry and set a template — much like alcohol and tobacco regulation — that many states would follow.
SourcesRelated timelines- Tobacco → — A taxed, regulated market, like tobacco's
- December 2013General sourceWell documented
Uruguay: First Country to Legalize
In December 2013, under President José Mujica, Uruguay became the first country in the world to fully legalize and regulate cannabis — from cultivation to sale — as an alternative to the violence of the illegal drug trade.
Why it matters: Uruguay broke the global prohibition consensus at the national level, showing a sovereign state could legalize cannabis and defy the UN treaty framework.
Sources- The Wilson Center. Marijuana: Made in Uruguay · reference
- October 17, 2018Primary sourceWell documented
Canada Legalizes Nationwide
With the Cannabis Act of 2018, Canada became the first major industrialized nation — and the second country after Uruguay — to legalize recreational cannabis nationwide, creating a regulated legal market across the entire country.
Why it matters: A wealthy G7 nation legalizing cannabis marked a turning point, accelerating global debate over whether prohibition had failed.
- the present dayPrimary sourceWell documented
Cannabis Today: The Rescheduling Era
By the 2020s, a majority of U.S. states had legalized medical or recreational cannabis even as it remained illegal federally. In 2024 the U.S. moved to reschedule marijuana from Schedule I to the far less restrictive Schedule III — a historic acknowledgment of its medical value.
Why it matters: After nearly a century of prohibition, cannabis is being rewritten in law as medicine and a regulated product — one of the fastest reversals in modern drug policy.