Medically Reviewed by
Jason Crawford

Article Last Updated on January 18, 2023

Cannabis drug policies have changed tremendously over the years in the United States. Before the state-level prohibition started at the beginning of the 20th century, weed was legal all over the US. It is only after the Controlled Substances Act of 1971 that cannabis was classified as a Schedule I drug and its use became illegal in every state. 

However, in recent years there’s a lot of talk about marijuana decriminalization on a federal level after a lot of US states have already decriminalized weed. 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 read these as well as the other cannabis-related articles on our site. And if you’d like to learn more about the history of cannabis, the cannabis legalization bill, and the overall legality of weed in the US, keep on reading.

Cannabis and Its Popularity

Even though we’ve previously written articles regarding the origin of cannabis, let’s briefly mention how the recreational use of cannabis increased in popularity among Americans.

The cannabis plant came to the US as a result of the migration of the Mexicans who brought this versatile plant with them after the Mexican revolution. Back in those days, cannabis was used to make a popular psychoactive drink in Mexico, which was brought to the US along with the cannabis consuming culture, but also for making fabrics, rope, and other products.

When Did Marijuana Laws Start Changing in the US?

The policy on cannabis use and possession slowly started to change around the 1930s along with Harry Anslinger’s anti-cannabis campaign. Anslinger spoke before Congress about how cannabis is allegedly an assassin of youth. This propaganda eventually led to the criminalization of marijuana possession all over the US. 

The first state that started implementing restrictions on weed was the state of Massachusetts, and the first one that prohibited cannabis cultivation was California, followed by Maine and Wyoming. As a result, the Marihuana Tax Act was passed by Congress in 1937 which increased the taxes for cannabis cultivation.

Cannabis Is Classified as a Schedule I Drug

The years after the Marihuana Tax Act was passed didn’t note changes in cannabis laws leading towards legalization, rather towards further regulation and prohibition of cannabis on a federal level. 

By 1970, president Richard Nixon started the “War on Drugs” which further spread the propaganda on cannabis. Both the Nixon campaign and the Marihuana Tax Act led to lawmakers in the federal government passing the Controlled Substances Act (CSA) on May 1st, 1971. This marijuana law classified cannabis as a Schedule I drug along with drugs such as heroin, LSD, and other addictive drugs stating that it has a high potential for dependency and no accepted medical use. The CSA controlled both recreational as well as medical cannabis which became illegal to sell and cultivate.

Recent US Federal and State Laws

Federal laws are very different from state laws when it comes to cannabis cultivation and cannabis use. At a federal level, cannabis is still classified as a Schedule I substance under the CSA act and its possession can get you in jail for up to 1 year, and at least a $1,000 fine for a first conviction. However, a lot of states have legalized medical marijuana or recreational marijuana on a state level, and the number of states legalizing it is only increasing.

The changes towards decriminalization (relaxation of criminal penalties due to marijuana use and possession) and legalization of weed slowly began during the Obama administration which urged federal prosecutors not to prosecute people who distribute cannabis for medical purposes in states where weed is legal under the Cole Memorandum

Marijuana laws changed during the presidency of Donald Trump which led to the Cole memorandum being rescinded with a memo by Attorney General Jeff Sessions in January 2018. The Sessions memorandum encouraged members of federal law enforcement to weigh in the seriousness of the crime as well as the impact of the crime on communities, though several US Governors and Senators from Alaska, California, Colorado, Nevada, New Jersey, Oregon, Vermont, and Washington expressed their displeasure on the memorandum.

The Joe Biden administration stated that they would reinstate the Cole memorandum in a different version during a congress session in February 2021.

The Marijuana Opportunity, Reinvestment and Expungement (More) Act

The MORE Act is the first piece of federal legislation that aims to deschedule cannabis from the Controlled Substances Act and it was introduced in 2019. The draft for this bill came as a result of a poll done by the Pew Research Center which stated that over 60% of Americans support legalizing weed for medical and recreational purposes. Even though The US House of Representatives passed the bill in 2020, the Senate still needs to support this decision in order to end federal marijuana prohibition and pave a new way towards federal marijuana legalization.

Medical Marijuana Laws in the US

The laws surrounding the legalization of medical marijuana have also changed since the Controlled Substances Act was passed in 1971. As more research was done about how cannabis can be used to treat certain medical conditions, California became the first state to legalize the use of medical marijuana in 1996. 

Medical marijuana is used to treat conditions such as epilepsy, chronic pain, ADHD, appetite loss, seizures, and other conditions on account of its anxiolytic, anti-inflammatory, antiepileptic, antipsychotic, and neuroprotective effects. As a result, the U.S. Food and Drug Administration has even approved two drugs, Marinol and Syndros, which contain THC as a treatment for patients who suffer from nausea as a result of cancer chemotherapy and also the drug Epidiolex for two severe types of epilepsy, Lennox-Gastaut syndrome and Dravet syndrome.

In 2018, the federal government legalized the use of CBD and CBD products sourced from the hemp plant with the passing of the 2018 Farm Bill (with THC levels lower than 0.3%) for medical marijuana users on a federal level.

Is Cannabis Legal in the US Today?

While cannabis isn’t legal on a federal level, 36 US states and the District of Columbia have legalized cannabis for medical use, while 18 states and the District of Columbia have legalized the recreational use of cannabis.

Where in the US Is Medical Cannabis Legal?

Not every state that has legalized cannabis for medical use has it legalized for recreational use. The following US states have legalized medical marijuana only:

  1. Alabama;
  2. Alaska; 
  3. Arizona;
  4. Arkansas; 
  5. California;
  6. Colorado;
  7. Connecticut;
  8. Delaware;
  9. District of Columbia;
  10. Florida;
  11. Hawaii;
  12. Illinois;
  13. Louisiana;
  14. Maine;
  15. Maryland; 
  16. Massachusetts;
  17. Michigan;
  18. Minnesota;
  19. Missouri; 
  20. Montana;
  21. Nevada;
  22. New Hampshire;
  23. New Jersey;
  24. New Mexico;
  25. New York;
  26. North Dakota;
  27. Ohio;
  28. Oklahoma;
  29. Oregon;
  30. Pennsylvania;
  31. Rhode Island;
  32. South Dakota;
  33. Utah;
  34. Vermont;
  35. Virginia;
  36. Washington;
  37. West Virginia.

Apart from these states which have legalized the consumption of medical marijuana for patients with a medical marijuana card, Mississippi is another state in which 69% of the voters have supported the legalization of medical marijuana through a ballot initiative. The initiative was tossed by the courts on account of the Mississippi state constitution which requires the consensus of all 5 congressional districts (Mississippi has only four districts after the 2000 Census count).

Where in the US is Recreational Adult Use of Cannabis Legal?

Even though the legalization of recreational cannabis is increasing, even fewer states in the US have legalized its use. The ones that have legalized the non-medical, adult use of cannabis include:

  1. Alaska; 
  2. Arizona;
  3. California;
  4. Colorado;
  5. Connecticut;
  6. District of Columbia;
  7. Illinois;
  8. Maine;
  9. Massachusetts;
  10. Michigan;
  11. Montana;
  12. Nevada;
  13. New Jersey;
  14. New Mexico;
  15. New York;
  16. Oregon;
  17. Vermont;
  18. Virginia;
  19. Washington.

Another state which will probably legalize the recreational use of cannabis is South Dakota. However, as a result of a lawsuit which argued that the Amendment A that would legalize cannabis was unconstitutional, the legalization of recreational cannabis has been prevented.

Final Thoughts and the Next Steps for Marijuana Legalization

At the moment, both recreational marijuana and medical marijuana are illegal on a federal level as a result of the Controlled Substances Act which classifies cannabis as a Schedule I drug. However, a lot of US states are considering the legalization of cannabis as the cannabis market expands on a global level and its use as a medicine is being researched in numerous studies.

The US Congress is also aiming to make a major reform in the legalization of cannabis on a federal level, so legal marijuana in the US is a likely scenario in the near future. We only need to wait and see what happens next.

A passionate advocate for the benefits of cannabis. Fraser Horton, who has a background in botany and a strong love of nature, has spent years researching how cannabis affects the body and mind. He established Leaf Nation in 2020, where he has devoted himself to educating people about the legalisation of marijuana and its safe and responsible use. Fraser is committed to highlighting cannabis’ potential for improving wellness and working to dispel the stigma associated with its use.


The information presented on this page is provided as a public service to aid in education and is derived from sources believed to be reliable. Readers are responsible for making their own assessment of the topics discussed here. In no event shall Leaf Nation be held reliable for any injury, loss or damage that could happen if using or abusing drugs.