Marijuana is a psychoactive drug made from the dried leaves and flowers of the hemp plant (cannabis sativa). Currently, the U.S. federal government classifies marijuana as a Schedule I substance—identifying it as having "a high potential for abuse" and "no currently accepted medical use," and placing it in the same league as opium and LSD. Because of its Schedule I status, it is illegal to buy, sell, grow, or possess marijuana in the United States, and people convicted of marijuana offenses face penalties ranging from fines to life imprisonment. In addition, the federal government, state governments, and local communities spend hundreds of millions of dollars annually on preventative programs such as Drug Abuse Resistance Education (DARE), in which police officers visit schools to teach young people to refrain from trying marijuana and other drugs.

Cannibis sativa has not always been classified as a dangerous narcotic...