A Brief History
Cannabis has been used by cultures the world over – from the hunters and gatherers of China, to the philosophers of ancient Greece – for thousands of years. With its roots in the Himalayan mountains, the cannabis plant has spread across the globe, its seed carried on the wind, often without the help of human hands. 
The history of cannabis use by humans goes back as far as 12,000 years, which places it among humanity’s oldest cultivated crops. Believed to have evolved in the harsh growing regions of Afghanistan, Mongolia, and southern Siberia, the plant spread over time to Europe, Africa and the Americas, where its use, for recreational and medical purposes, is now ubiquitous. 
Roots in Asian Soil
Arriving in Europe
Brought to Germany from Russian and Ukraine by Germanic tribes, cannabis was used among the British infantry and populace during the Anglo-Saxon invasions of the 5th Century. Only, it wasn’t until the mid-19th Century that Western physicians took an interest in the herb. Reports even suggest that Queen Victoria was given cannabis by her doctor to relieve menstrual pain. 
With the introduction of syringes and the advent of pharmaceutical drugs like Aspirin near the end of the 19th century, the widespread medicinal use of cannabis came to a rather abrupt end.
Because injectable drugs like morphine were trusted to take effect much faster when treating acute conditions, and Aspirin became the household pain reliever of choice for chronic pain, the practical need for, and use of, cannabis waned. Of course, it’s important to remember that the line of products available today to smoke, vape, eat, or apply topically, was no doubt absent then.
In line with the legislative sentiment of most nations at the time, cannabis was outlawed in the UK in 1928, following an international drug conference in Geneva, Switzerland. At the conference, Egyptian delegate Mohammed El Guindy made significant pleas for cannabis to be listed, alongside opium, as a dangerous drug. 
Coming to the Americas
At the beginning of the 20th Century, the notion of medical cannabis was mostly greeted with optimism when it was introduced the United States. At the time, cannabis oil was brought to market by a trusted British pharmaceutical company. In fact, it was common then to find cannabis oil in medicine cabinets across the continent.
While oils and tinctures occupied apothecary shelves, cannabis flowers came south from Mexico with immigrants fleeing the Mexican Revolution of 1910-1911. While these flowers were traditionally used by Mexicans for therapeutic purposes, a well-backed propaganda campaign soon pinned cannabis, of all forms, as an evil force brought on by outside menaces.
Many early prejudices against cannabis were thinly veiled racist fears of its smokers, often promulgated by reactionary newspapers. Mexicans and African Americans were frequently blamed for cannabis and its ills – with the effects of consumption being noted as property crimes, seduction, and even murder. 
Because no distinction was ever made between the medical merits of cannabis, and the inflamatory claims and notoriety being levelled on the plant by opponents, cannabis was outlawed in every then-29 states. In Canada, authorities first added cannabis to the list of banned substances in 1923.
In 1930, Harry Anslinger became the first commissioner of the Federal Bureau of Narcotics (FBN). He worked hard to outlaw cannabis in all states, and it only took seven years from the introduction of the Marijuana Tax Act to put both cannabis and hemp under the administration of the Drug Enforcement Agency (DEA), a mandate the DEA maintains today.
While significant strides have been made in many states, both in the context of recreational and medical use, the DEA still classifies cannabis as a Schedule 1 controlled substance, along with LSD and heroin. Its classification means it has a high potential for abuse and addiction, with no accepted medical uses. 
Canada, on the other hand, proved one of the first countries to adopt federal laws allowing cannabis patients to medicate. Most recently, the country has moved one step further, indicating it hopes to legalize cannabis for adult use in 2018. The move would make Canada only the second country, behind Uruguay, to legalize the drug for recreational consumption.