Until 1913, marijuana was legal throughout the United States under both state and federal law.16 Beginning with California in 1913 and Utah in 1914, however, states began outlawing marijuana, and by 1930, 30 states had adopted marijuana prohibition. Those state‐level prohibitions stemmed largely from anti‐immigrant sentiments and particularly from racial prejudice against Mexican migrant workers, who were often associated with the use of the drug. Prohibition advocates attributed terrible crimes to marijuana and the Mexicans who smoked it, stigmatizing marijuana use and the purported “vices” that resulted from it.17 Meanwhile, film productions, such as the 1936 movie Reefer Madness, presented marijuana as “Public Enemy Number One” and suggested that its consumption could lead to insanity, death, and even homicidal tendencies.18
Starting in 1930, the Federal Bureau of Narcotics pushed states to adopt the Uniform State Narcotic Drug Act and to enact their own measures to control marijuana distribution.19 In 1937, Congress passed the Marihuana Tax Act, which effectively outlawed marijuana under federal law by imposing a prohibitive tax; stricter federal laws followed.20 The 1952 Boggs Act and the 1956 Narcotics Control Act established mandatory sentences for drug‐related violations; a first‐time offense for marijuana possession carried a minimum sentence of 2–10 years in prison and a fine of up to $20,000.21 While those mandatory sentences were mostly repealed in the early 1970s, President Ronald Reagan reinstated them under the Anti‐Drug Abuse Act of 1986. The current federal legislation controlling marijuana possession, use, and distribution is the Controlled Substances Act, which was published in 1971 and classifies marijuana as a Schedule I drug. This category is for drugs that, according to the Drug Enforcement Administration, have “no currently accepted medical use and a high potential for abuse” as well as a risk of creating “severe psychological and/or physical dependence.”22
Despite this history of increasingly draconian federal action against marijuana (and other drugs), individual states have been backing away from marijuana prohibition since the 1970s. Eleven states decriminalized the possession or use of limited amounts of marijuana between 1973 and 1978, including, in chronological order, Oregon, Alaska, California, Colorado, Maine, Minnesota, Ohio, Mississippi, New York, North Carolina, and Nevada.23 However, not all states followed such a straightforward path toward marijuana liberalization. Alaska, for example, decriminalized marijuana use and possession in one’s home in 1975, but in 1990, a voter initiative recriminalized possession and use of marijuana. A second decriminalization wave began when Nevada defelonized marijuana possession in 2001; 19 more states and the District of Columbia have since adopted similar reforms.24 By the mid‐1990s, amid mounting scientific evidence pointing to marijuana’s potential medicinal benefits—including treating chronic pain, glaucoma, Alzheimer’s, Parkinson’s, epilepsy, and other medical conditions—various states began to legalize medical marijuana but restricted access only to patients who satisfied strict criteria.25 Over the past two decades, 33 states and the District of Columbia have legalized marijuana for medical purposes, significantly expanding the number of patients eligible for medical marijuana prescriptions. In some states, these medical regimes approximate de facto legalization.26
The most dramatic cases of states undoing earlier prohibitions and departing from federal policy have occurred in those states that have legalized marijuana for recreational as well as medical purposes (Colorado, Washington, Oregon, Alaska, California, Nevada, Maine, Massachusetts, Illinois, Michigan, and Vermont). Nearly every state that has legalized marijuana thus far has done so through citizen‐driven ballot initiatives. After formally legalizing marijuana, states normally take one to two years to set up regulatory regimes, establish licensing guidelines, and impose marijuana taxes; only then can the first marijuana shops open.
In the 2020 elections, more states’ ballots included measures to liberalize their marijuana laws. New Jersey, South Dakota, Arizona, and Montana passed ballot measures legalizing marijuana for recreational use. Mississippi and South Dakota voters likewise approved ballot measures legalizing medical marijuana. As of November 2020, the Marijuana Policy Project listed 23 states with bills to legalize marijuana, 14 with bills to decriminalize marijuana, and 12 with bills to create medical marijuana programs.27
Although states’ paths differ in some ways, most follow a pattern of first decriminalizing, then medicalizing, and then legalizing. One exception is Michigan, which did not decriminalize marijuana statewide prior to legalizing medical marijuana—although many cities had adopted local decriminalization laws by that time.28 Another is Vermont, which legalized medical marijuana in 2004, nine years before decriminalizing it in 2013.29 For states following the usual decriminalize‐medicalize‐legalize pattern, their experiences with decriminalization and medical legalization inform the expected effects of total legalization, since these partial measures often serve as steps toward that end.