Harrison Act

Many of the states also passed their own laws prohibiting the sale of opiates by 1916. A narcotics division was established in the U.S. Treasury Department that enforced the ban on all narcotics sales. The Harrison Act did have an effect on the supply of drugs; it was reflected by an increased demand for drugs on the black market by the mid-1920s. This demand led to organized crime expanding from bootlegging under Prohibition to include drug trafficking as well.

Well-known crime leaders turned away from the more competitive production and selling of rum running to drug trafficking on an international basis. The goal of organized crime was to regulate the supply of drugs into the country, therefore keeping demand and the price of narcotics high. They purchased legitimate warehouses, antique stores, and art galleries to store illegal shipments of drugs and launder drug money. What law enforcement considered a narcotics epidemic swept the country by the late 1920s.

The ban on alcohol from Prohibition followed the Harrison Act by five years. Others sought to ban tobacco, which was considered to have medicinal value in the nineteenth century. That opinion markedly changed through the twentieth century leading to the Cigarette Labeling and Advertising Act of 1965. The act required tobacco companies to place health warnings on cigarette packaging and advertising. By the 1990s tobacco smoking was becoming increasingly unacceptable though still legal.

Other drugs gained the attention of the public and legislatures. In 1915 California became the first state to criminalize marijuana use. Many other states passed similar laws over the next two decades, and Congress passed a federal law, the Marijuana Tax Stamp Act in 1937 banning marijuana use. Efforts to legalize marijuana use for medicinal purposes gained limited success in several states by the early twenty-first century.

The social upheavals of the 1960s brought greater attention to marijuana and hallucinogens that had gained popularity with the country's youth. In addition, many soldiers sent to the Vietnam War (1954–75; a controversial war in which the United States aided South Vietnam in its fight against a takeover by Communist North Vietnam) in the late 1960s were introduced to marijuana and heroin in Southeast Asia. In response, Congress passed the Comprehensive Drug Abuse Prevention and Control Act in 1970. The act created the position of a top government administrator, referred to as a "Drug Czar," charged with coordinating the anti-drug law enforcement efforts of many agencies.

Through the 1970s states passed drug laws that included tough sentencing measures, in some cases fifteen years to life in prison for selling small amounts of drugs. This trend favoring punishment over rehabilitation continued to grow as drug use expanded. In the mid-1980s President Ronald Reagan (1911–2004; served 1981–89) introduced the "War on Drugs." At the time, a rise in use of crack cocaine, an inexpensive, powerful form of the drug, was spreading quickly in the nation's inner cities. Along with crack cocaine came a rise in gang activity and violence.

Congress passed the Anti-Drug Abuse Acts of 1986 and 1988. The acts greatly increased law enforcement efforts against drug offenders including border patrols. The act also provided for a forfeiture of property associated with committing drug crimes or purchased from drug profits. Regarding punishment, the acts increased mandatory sentences, provided funding assistance for building more prisons, and established the death penalty for drug-related killings.

The courts supported this strong stance by ruling that a mandatory life sentence for selling cocaine was not cruel and unusual punishment. By the late 1990s the federal government and states were spending some $40 billion a year on the drug war. The fight even went beyond the nation's borders to Columbia, a key source for cocaine.

The United States maintained stiffer drug laws and punishment than most European countries. Despite this long and expensive fight against drug use, by the early twenty-first century some four million heavy drug users still existed in the United States and some 400,000 were in prisons convicted of drug offenses. Some drug use was down, such as cocaine, while others were up, like heroin. Drug trafficking remained very profitable despite a decrease in protection against unlawful search and seizure.