The history of cannabis in the United States is a complex journey shaped by shifting social attitudes, political movements, and evolving laws. From early 20th-century prohibition to the sweeping legalization efforts of the 21st century, cannabis policy has reflected broader debates about medicine, criminal justice, and individual freedom. This timeline traces key moments in U.S. cannabis history—highlighting landmark legislation, court rulings, and cultural turning points that have shaped how the country views and regulates the plant today.
This is a work in progress.
Texas - June 22, 2025
Gov. Greg Abbott vetoed a controversial state ban on THC products and soon after called a special legislative session, urging lawmakers to impose strict regulations instead.
Texas - June 21, 2025
Governor Greg Abbott (R) signed House Bill 46 into law, expanding the state’s limited medical cannabis program, known as the Texas Compassionate Use Program.
United States - Dec. 2, 2022
The Medical Marijuana and Cannabidiol Research Expansion Act was signed into law, making it easier to conduct medical research on cannabis. It is the first standalone cannabis reform legislation ever enacted at the federal level.
Alabama - May 17, 2021
On May 17, 2021, Governor Kay Ivey signed Senate Bill 46—the Darren Wesley "Ato" Hall Compassion Act—into law, legalizing medical cannabis. The law prohibits sales of raw cannabis and edible products like cookies or candies.
Arizona - Jan. 22, 2021
The first state-licensed recreational marijuana sales began in Arizona, making it the fastest state in U.S. history to move from voter approval to retail sales.
Arizona - Nov. 3, 2020
Arizona Proposition 207, known as the Smart and Safe Arizona Act, passes with 60% of voters approving the measure which legalizes adult recreational use of marijuana.
United States - Dec. 20, 2018
The 2018 Farm Bill, signed into law on December 20, 2018, marked a major shift in U.S. cannabis policy by legalizing industrial hemp at the federal level. For the first time since 1937, hemp—defined as cannabis containing less than 0.3% THC—was removed from the Controlled Substances Act, effectively distinguishing it from marijuana. The bill allowed farmers nationwide to grow and sell hemp commercially, and it opened the door for expanded research, interstate commerce, and crop insurance for hemp producers.
United States - Dec. 16, 2014
After six failed attempts, the Rohrabacher-Farr amendment passed the House and became law in December 2014 as part of an omnibus spending bill. Originally introduced by Rep. Maurice Hinchey in 2001, it prohibits the U.S. Department of Justice from using federal funds to interfere with state medical cannabis laws. It marked the first time either chamber of Congress voted to protect medical cannabis patients, representing a historic milestone for federal cannabis reform. However, the amendment does not change the legal status of cannabis and must be renewed each fiscal year to remain in effect.
Alabama - April 1, 2014
Governor Robert Bentley signs Carly's Law, permitting the University of Alabama at Birmingham to provide non-psychoactive CBD oil to children with debilitating seizures as a clinical study.
Washington - Dec. 6, 2012
Washington voters approve Initiative 502 legalizing recreational marijuana for adults 21 and older.
Arizona - Nov. 2, 2010
In 2010, Arizona voters approved Proposition 203, legalizing medical marijuana for patients with qualifying conditions.
Alaska - Nov. 4, 1998
Almost 69% of Alaska voters approve Measure 8, an initiative allowing patients with qualifying conditions to possess and use marijuana with a doctor's approval.
Washington - Nov. 3, 1998
Medical marijuana is legalized after Initiative 692 passes with 59% of the vote.
California - Nov. 5, 1996
California voters approved Proposition 215, also known as the Compassionate Use Act, making it the first state in the U.S. to legalize medical marijuana.