The War on Drugs and Cannabis

The War on Drugs and Cannabis: History, Failures, and Reform

A comprehensive look at how US drug policy shaped — and distorted — cannabis law, enforcement, science, and society for over a century. Cannabis laws vary by state. This guide is for adults 21+ in legal jurisdictions.

What Is the War on Drugs and How Did Cannabis Become Its Primary Target?

The phrase "War on Drugs" was coined by President Richard Nixon on June 17, 1971, when he declared drug abuse "public enemy number one" and called for a major new initiative to combat it. But cannabis prohibition in the United States stretches back much further — and understanding that longer arc is essential to grasping where American cannabis policy stands today.

The first major federal action against cannabis came with the Marihuana Tax Act of 1937, which effectively banned commercial cannabis by imposing prohibitive taxes and onerous regulations on its sale and transfer. The legislation was pushed through Congress largely by Harry Anslinger, the head of the Federal Bureau of Narcotics, who used racially charged propaganda — linking cannabis to Black jazz musicians and Mexican immigrants — to stoke public fear. Scientific testimony opposing the ban, including from the American Medical Association, was largely dismissed.

The modern prohibition framework solidified with the Controlled Substances Act of 1970, which classified cannabis as a Schedule I controlled substance — a category defined by high abuse potential and no accepted medical use. The Nixon administration placed cannabis in Schedule I despite a recommendation from its own advisory commission (the Shafer Commission) to decriminalize personal possession. Nixon rejected the recommendation outright. Years later, his domestic policy chief John Ehrlichman admitted in a 2016 interview that the War on Drugs was deliberately designed to target political enemies: anti-war protesters and Black communities.

Through the 1980s and 1990s, under Presidents Reagan, Bush, and Clinton, the War on Drugs intensified dramatically. Mandatory minimum sentencing laws, "three strikes" provisions, asset forfeiture policies, and the "Just Say No" public relations campaign all converged to make cannabis enforcement one of the defining features of American criminal justice. By the mid-1990s, cannabis arrests had climbed to nearly 700,000 per year. Understanding this history is critical for any reader exploring cannabis explainers or researching the current legal landscape by state.

How It Works: The Mechanisms of Cannabis Prohibition

To understand how the War on Drugs functions in practice, think of it as a layered system of overlapping rules — like a series of locked doors between a plant and the person who might want to use it. Each door represents a different level of law or policy: federal scheduling, state criminal codes, local ordinances, banking regulations, and tax law. Even in states where cannabis is legal, some of those doors remain locked at the federal level.

Federal scheduling is the foundation. Because cannabis is Schedule I, it is treated like heroin under federal law — meaning no prescriptions can be written, no interstate commerce is permitted, and federal research is severely restricted. Researchers who want to study cannabis must navigate a labyrinthine approval process through the DEA and NIDA (National Institute on Drug Abuse), which historically supplied only low-quality cannabis for research. This has created enormous gaps in the clinical evidence base for cannabis-based medicine — gaps that ironically are then cited as justification for maintaining Schedule I status.

Tax law adds another layer. IRS Code Section 280E, originally designed to prevent drug traffickers from deducting business expenses, applies to all Schedule I businesses — including state-licensed cannabis dispensaries. This means legal cannabis companies can pay effective tax rates of 50–70%, compared to 21% for other businesses, severely limiting their ability to grow and compete. Explore more about how this affects the medical cannabis industry.

Banking restrictions stem from federal anti-money-laundering laws. Because cannabis remains federally illegal, most banks and credit unions refuse to serve cannabis businesses, forcing them to operate largely in cash — creating safety risks and operational challenges. Despite the SAFE Banking Act passing the House of Representatives multiple times, it has repeatedly stalled in the Senate as of this writing.

At the state level, the patchwork of laws creates a geography of access. In the 24 states with adult-use legalization, adults 21+ can typically purchase cannabis at licensed retailers. In the remaining states, possession can still result in arrest, fines, and incarceration. Our state-by-state guide breaks down exactly what's legal where.

Key Data & Research: What the Numbers Actually Show

Half a century of data on drug war outcomes paints a consistent picture: prohibition has failed to achieve its stated goals while generating enormous collateral damage. Here is a summary of the most important research findings:

"You want to know what this was really about? The Nixon campaign in 1968, and the Nixon White House after that, had two enemies: the antiwar left and Black people. We knew we couldn't make it illegal to be either against the war or Black, but by getting the public to associate the hippies with marijuana and Blacks with heroin, and then criminalizing both heavily, we could disrupt those communities." — John Ehrlichman, Nixon's domestic policy chief, Harper's Magazine, 2016

Practical Implications: How the Drug War Still Affects Cannabis Consumers Today

For everyday cannabis users, the legacy of the War on Drugs is not just a history lesson — it's a set of present-day realities that shape access, risk, and rights. Here's how it plays out in practice:

Drug testing and employment: Federal contractors, transportation workers, and many private employers continue to test for cannabis regardless of state law. Because THC metabolites can remain detectable for weeks, even infrequent users may test positive long after any impairment has passed. Our drug test guide explains how cannabis testing works and what consumers should know. The mismatch between state legality and federal employment standards is one of the most consequential day-to-day consequences of the drug war's unfinished legacy.

Criminal records: Tens of millions of Americans have cannabis-related convictions on their records — often for simple possession of small amounts. These records create barriers to employment, housing, student loans, professional licensing, and in some states, voting rights. Many states with legalization have passed expungement laws, but implementation has been slow and inconsistent. If you have a prior cannabis conviction, the legal landscape for expungement varies significantly by your state.

Medical access: The Schedule I classification has meant that patients who could benefit from medical cannabis have faced decades of delayed research. Cannabidiol (CBD) received its first FDA-approved pharmaceutical form — Epidiolex — only in 2018. The full therapeutic potential of cannabinoids including THC, CBD, CBG, and others remains understudied relative to their apparent clinical promise. Learn more about specific cannabis effects that are only now being systematically studied.

Market access and quality: In states without legal markets, consumers who use cannabis have no access to lab-tested, regulated products. They cannot know the potency, purity, or terpene profile of what they're purchasing. This is a direct public safety consequence of prohibition — not of cannabis use itself.

Interstate travel: Crossing state lines with cannabis remains a federal crime regardless of whether both states have legalized it. Federal jurisdiction applies to all interstate travel, including roads, airports, and train stations — creating legal traps for consumers unfamiliar with these nuances.

Common Questions & Misconceptions About the War on Drugs

Myth #1: Cannabis Was Always Illegal in the United States

Many people assume cannabis has always been prohibited, but that is far from the case. For most of American history, cannabis — often called hemp — was a legal and commercially grown agricultural crop. Hemp cultivation was encouraged during the colonial era, and cannabis-based medicines were widely available in US pharmacies until the early 20th century. Federal prohibition only began in 1937, and even then, it was implemented through a tax scheme rather than an outright ban. The plant was used legally by Americans for food, fiber, medicine, and recreation for centuries before prohibition. Strains like today's popular varieties…