While the plant has been harvested, cultivated and consumed for thousands of years, its social stigma and status as an illicit substance in American history dates back to the early 1900s, just after the Mexican Revolution.
During this time, there was an influx of immigration across the Mexican border into the United States. As they settled into their new homes, Mexican immigrants brought with them their culture, native language and customs, all while attempting to find jobs during a time of massive unemployment and general social unrest caused by the Great Depression. While those in the U.S. were already familiar with cannabis due to its prevalence in various tinctures and medicines at the time, the name that Mexican immigrants used—"marihuana"—was a foreign term and therefore began to fuel resentment, fear and overall negative apprehension amongst Americans. Because of this, the American media began to use the term to further perpetuate racist stereotypes against Mexican immigrants and their subsequently deemed recreational drug use and "dangerous behavior." This completely sidestepped the reality that derivatives from the cannabis plant (i.e. "marihuana") were already commonly found in American medicine cabinets.
Over the course of roughly four decades, cannabis went from being commonly used as plant medicine to being deemed among the most dangerous substances according to the federal government,despite having a 5,000+ year history as a natural substance with therapeutic value.
In other words, the demonization of cannabis was essentially an easy vehicle to further demonize, control and give a reason to deport Mexican immigrants, much like San Francisco did when an influx of Chinese immigrants led to the panic-induced ban of opium decades prior. San Francisco's landmark ban of opium dens in 1875 is commonly regarded as the first anti-drug legislation passed in America. Soon thereafter, the Harrison Narcotics Tax Act of 1914 was passed on a federal level, imposing restrictions on the psychoactive drug (opium), setting the stage for Marijuana to follow suit.
While cannabis was first regulated by the government as early as 1906 (via the Pure Food and Drug Act), the climate noticeably began to shift due to the vocal protests against marijuana being made by Federal Bureau of Narcotics Commissioner Harry Anslinger. As a result of his widespread anti-drug campaigning and political influence, he received support from President Franklin D. Roosevelt for the adoption of the Uniform State Narcotic Act, which was a statute created in response to the lack of restrictions found in the Harrison Act of 1914 that suggested the prohibition of cannabis use at the state level.
Several years later, the Marihuana Tax Act of 1937 was passed, making the individual possession and sale of marijuana illegal nationwide. Technically, the act did not make medicinal marijuana illegal but it did make it nearly impossible to utilize, such as through an expensive tax system, extensive paperwork and severe criminal penalty if the tax was not paid. In 1970, the Controlled Substance Act introduced the federal scheduling system, which classifies all substances based on medicinal value, harmfulness and potential for abuse or addiction.
Over the course of roughly four decades, cannabis went from being commonly used as plant medicine to being deemed among the most dangerous substances according to the federal government, despite having a 5,000+ year history as a natural substance with therapeutic value. When examining the current landscape of cannabis in the United States, it is vital to look at its history and how the term "marihuana" was more criminalized and advertised as an anti-immigration response and less of a call to action to presumably protect the safety of Americans.