The legal history of cannabis in the United States began with state-level prohibition in the early 20th century, with the first major federal limitations occurring in 1937. Starting with Oregon in 1973, individual states began to liberalize cannabis laws through decriminalization. In 1996, California became the first state to legalize medical cannabis, sparking a trend that spread to a majority of states by 2016. In 2012, Washington and Colorado became the first states to legalize cannabis for recreational use.
In the United States, the non-medical use of cannabis is legalized in 24 states and decriminalized in 7 states, as of November 2023. Decriminalization refers to a policy of reduced penalties for cannabis offenses, typically involving a civil penalty for possessing small amounts, instead of criminal prosecution or the threat of arrest. In jurisdictions without penalty the policy is referred to as legalization, although the term decriminalization is sometimes used for this purpose as well.
In the United States, increased restrictions and labeling of cannabis as a poison began in many states from 1906 onward, and outright prohibitions began in the 1920s. By the mid-1930s cannabis was regulated as a drug in every state, including 35 states that adopted the Uniform State Narcotic Drug Act. The first national regulation was the Marihuana Tax Act of 1937.
Cannabis in Oregon is legal for both medical and recreational use. In recent decades, the U.S. state of Oregon has had a number of legislative, legal, and cultural events surrounding use of cannabis. Oregon was the first state to decriminalize the possession of small amounts of cannabis, and among the first to authorize its use for medical purposes. An attempt to recriminalize possession of small amounts of cannabis was turned down by Oregon voters in 1997.
In the United States, the use and possession of cannabis is illegal under federal law by way of the Controlled Substances Act of 1970. Cannabis is classified as a Schedule I drug under the Controlled Substances Act, determined to have a high potential for abuse and no accepted medical use, prohibiting its use for any purpose. Despite this, most states have passed laws to legalize the use of cannabis for medical purposes, while close to a majority of states have legalized for recreational use.
In the U.S. state of Maine, marijuana (cannabis) is legal for recreational use. It was originally prohibited in 1913. Possession of small amounts of the drug was decriminalized in 1976 under state legislation passed the previous year. The state's first medical cannabis law was passed in 1999, allowing patients to grow their own plants. The cities of Portland and South Portland decriminalized the possession and recreational use of marijuana in 2013 and 2014, respectively.
Cannabis in Vermont as of May 2004 is legal for medical use, and legal for recreational use as of July 1, 2018.
Cannabis in South Dakota is legal for medical use as of July 1, 2021, having been legalized by a ballot initiative on November 3, 2020. Prior to then, cannabis was fully illegal, with South Dakota being the only U.S. state which outlawed ingestion of controlled substances. Testing positive for cannabis can be a misdemeanor offense. South Dakota would have become the first state in US history to legalize recreational and medical cannabis simultaneously, but an amendment legalizing recreational marijuana that was approved in the same election was struck down as unconstitutional the following February. The challenge claimed the amendment violated Amendment Z, the "Single-Subject Rule". The decision was appealed to the South Dakota Supreme Court, which upheld the lower court's decision on November 24, 2021.
Cannabis in Wisconsin is illegal for recreational use. Possession of any amount is punishable by up to 6 months in prison and a $1000 fine for a first offense. A second offense is punished as a felony with up to 3.5 years in prison and up to a $10,000 fine. At the local level, however, numerous municipalities and counties have decriminalized cannabis or lessened penalties for minor possession offenses. Medical use is legal only in the form of low-THC cannabis oil.
Cannabis in North Dakota is legal for medical use but illegal for recreational use. Since 2019 however, possession under a 1/2 ounce has been decriminalized in the sense that there is no threat of jail time, though a criminal infraction fine up to $1,000 still applies. The cultivation of hemp is currently legal in North Dakota. In November 2018, the state's voters voted on recreational marijuana legalization, along with Michigan; the measure was rejected 59% to 41%. Two groups attempted to put marijuana legalization measures on the June 2020 Primary and the November 2020 elections, but were prevented from doing so by the COVID-19 pandemic.
Cannabis in Nevada became legal for recreational use on January 1, 2017, following the passage of Question 2 on the 2016 ballot with 54% of the vote. The first licensed sales of recreational cannabis began on July 1, 2017.
Cannabis in Arizona is legal for recreational use. A 2020 initiative to legalize recreational use passed with 60% of the vote. Possession and cultivation of recreational cannabis became legal on November 30, 2020, with the first state-licensed sales occurring on January 22, 2021.
Cannabis in North Carolina is illegal for any use except for very limited medical usage, though decriminalized for possession of 0.5 ounces or less for individuals with three or fewer misdemeanor convictions.
Cannabis in Missouri is legal for recreational use. A ballot initiative to legalize recreational use passed by a 53–47 margin on November 8, 2022. Possession for adults 21 and over became legal on December 8, 2022, with the first licensed sales occurring on February 3, 2023.
Cannabis in New Mexico is legal for recreational use as of June 29, 2021. A bill to legalize recreational use – House Bill 2, the Cannabis Regulation Act – was signed by Governor Michelle Lujan Grisham on April 12, 2021. The first licensed sales of recreational cannabis began on April 1, 2022.
Cannabis in Maryland is legal for medical use and recreational use. Possession of up to 1.5 ounces and cultivation of up to 2 plants is legal for adults 21 years of age and older. In 2013, a state law was enacted to establish a state-regulated medical cannabis program. The program, known as the Natalie M. LaPrade Maryland Medical Cannabis Commission (MMCC) became operational on December 1, 2017.
Cannabis in Florida is illegal for recreational use. Possession of up to 20 grams is a misdemeanor offense, punishable by up to a year in jail, a fine of up to $1000, and the suspension of one's driver's license. Several cities and counties have enacted reforms to apply lesser penalties, however.
Cannabis in Ohio will become legal for recreational use on December 7, 2023. Since 1975, possession of up to 100 grams has been decriminalized, with several of the state's major cities having enacted further reforms. On November 7, 2023, voters approved Issue 2 by a 57–43 margin to legalize cannabis for recreational use.
Cannabis in Michigan is legal for recreational use. A 2018 initiative to legalize recreational use passed with 56% of the vote. State-licensed sales of recreational cannabis began in December 2019.