Fraser Horton
Fraser Horton
Last Updated on September 5, 2021

Looking back at the history of marijuana, one thing is certain – the drug laws regarding cannabis use have significantly changed over the years. From the rising popularity of the cannabis plant during the 1900s to the cannabis prohibition and the decriminalization of weed at the start of the 21st century, the legality of cannabis has undergone many changes, but when was it made illegal?

For all of you out there who are interested in knowing how long people have been smoking weed as well as when marijuana was classified as a Schedule I drug, you can visit these and other articles on our site. However, if you’re interested in learning how and when cannabis was made illegal, read on.

How Did Marijuana Become Popular in the US?

It’s a fact that the cannabis plant was widely popular all over the world before the recreational use of weed became common among Americans. Moreover, the legalization laws in the 21st century resulted in medical marijuana becoming a treatment option for various medical conditions. But let’s start at the beginning, and go over how marijuana use became popular in the US.

Marijuana wasn’t as popular among Americans until the Mexican immigrants brought “marihuana” along with their “potación de guaya,” a popular 20th century drink from Mexico, to the US after the Mexican revolution. 

Prior to this, hashish was quite popular in America, and a lot of celebrities experimented with it. After the Mexican Civil War, the recreational use of cannabis became all the rage and was becoming the most widely consumed drug.

The Road to Marijuana Becoming Illegal in the US

After the Mexican Revolution, a lot of Mexican immigrants started moving to Texas and all over the US, bringing their cannabis-smoking habits with them. Even though weed became popular for its recreational and medical use across the US, the attitude towards weed changed after a while because some people (and especially the media), started to connect it with people of lower social classes and immigrants.

The first state that restricted the use of weed was Massachusetts. People who wanted to use cannabis, or “Indian hemp” as they called it, needed to have a prescription. Cannabis cultivation, on the other hand, or the cultivation of locoweed, was first prohibited in California in an attempt to regulate psychoactive substances and opiates. Followed by Wyoming and Maine, the road to marijuana prohibition was paved.

Harry Anslinger and Cannabis

As the popularity of weed decreased, more people became against it, and people even started to speak out. One of them was Harry Anslinger, an avid speaker in Congress in favor of marijuana prohibition. Anslinger, who became the first director of the Federal Bureau of Narcotics, launched an anti-cannabis campaign in the 1930s and called marijuana an assassin of youth in one of his reports. He went on to issue further racist and anti-cannabis statements and also made the propaganda movie “Reefer Madness.” This period resulted in the criminalization of marijuana possession all over the US. 

The Marijuana Tax Act of 1937

The last step before the prohibition of marijuana was the passing of the Marihuana Tax Act of 1937 by Congress. Even though the American Medical Association claimed that cannabis might have various medical benefits, this act essentially banned marijuana across the US. Cannabis cultivators had higher taxes and more regulations, and if you were to violate the strict laws, you could face imprisonment or a fine of up to $2,000.

Cannabis Becomes Classified as a Schedule I Drug

The 1970s in the United States was marked by president Richard Nixon’s “War on Drugs” campaign, which focused on preventing drug abuse disorders by prohibiting drug use. The campaign was followed by the passing of the Controlled Substances Act (CSA) on May 1st, 1971 by the lawmakers in the federal government which was part of the Comprehensive Drug Abuse Prevention and Control Act following the Marijuana Tax Act of 1937. 

This new marijuana law prohibited the use of marijuana for both recreational and medical purposes and classified cannabis as a Schedule I drug with “high potential of abuse and no accepted medical use” along with LSD, heroin, and other addictive drugs. New regulatory bodies were formed which would enforce the drug schedule including the Drug Enforcement Administration (DEA), the Bureau of Narcotics and Dangerous Drugs, and the Bureau of Drug Abuse Control.

The Reagan administration added new drug laws as a way to stop cocaine and heroin trafficking, but they also applied to weed. In an effort to stop drug kingpins, the authorities made new sentencing laws and increased the prison terms for cannabis distribution, as well as other drugs. So, medical cannabis and recreational cannabis were illegal until new legalization laws were passed at the end of the century.

Marijuana’s Rise to Popularity

A lot has changed regarding marijuana use in the past 20-30 years. A few years after the CSA was passed, state and federal laws began to differ. A report in The New York Times even claimed that the cannabis policy “has its origins in racism and xenophobia and the principal effect has been to ruin the lives of generations of people.” 

Over time, the marijuana policy started changing as states began to liberalize cannabis laws through decriminalization, starting with Oregon in 1973. The legalization of medical and recreational cannabis ensued, even though the DEA and the FDA still believe that cannabis should remain a Schedule I drug.

The Laws on Medical Marijuana

Medical marijuana laws have also changed since the CSA, as California became the first state to legalize the medicinal use of cannabis in 1996. Following their example, other states started legalizing medical cannabis including Washington, Oregon, Alaska, Nevada, Maine, Colorado,  Hawaii, and ultimately a total of 36 states and the District of Columbia have already legalized the medical use of cannabis.

Medical marijuana can be used for its “antiepileptic, anxiolytic, antipsychotic, anti-inflammatory, and neuroprotective effects” as a way to treat several medical conditions including chronic pain, epilepsy, ADHD, nausea, seizures, appetite loss, anxiety, and other mental health conditions.

After the passing of the 2018 Farm Bill,  the federal government legalized the use of CBD and CBD products with THC levels lower than 0.3% on a federal level for medical marijuana users who have a valid medical marijuana card.

Final Thoughts on When Cannabis Became Illegal

Marijuana legalization is a topic in a lot of countries all over the world today, but that wasn’t always the case. In fact, marijuana has been banned and criminalized as the “War on Drugs” was ongoing in the past century. The US finally banned the use and cultivation of weed with the Controlled Substances Act in 1971, and cannabis has remained a Schedule I illegal drug on a federal level ever since.

However, at the turn of the new century, a lot of states started legalizing medical cannabis on a state level as a way to effectively treat or control a lot of medical conditions. The laws concerning the recreational use of cannabis have also changed as more and more states across the US have legalized it, and we only need to wait to see what happens next.


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