Though hemp was grown as a fiber by the earliest American colonists, and cannabis was used as an ingredient in medicines throughout the 19th century, recreational cannabis smoking first took on a negative connotation in the American cultural imagination when people began to associate it with Mexican immigrants arriving in the country after the revolution of 1910.

Many Mexican laborers smoked marijuana to unwind, as a cheaper alternative to alcohol during Prohibition. The drug became associated with immigrants, tied up in xenophobic fears and resentments during the Great Depression.

Soon researchers claimed baseless links between marijuana use and antisocial behavior, crime, murder and insanity. One by one, states passed legislation outlawing the drug.

In 1936, the film Reefer Madness released. Originally conceived as a morality tale to warn parents against the dangers of cannabis, it was recut into an exploitation film, a lurid melodrama about a group of dope-smoking teens who descend into a hell of murder, suicide and madness brought on by the infernal herb.

Though Reefer Madness was the most famous anti-weed screed, it was soon followed by many imitators, including Assassin of Youth, where all-night marijuana parties lead to violence, and Marihuana, where an innocent girl winds up impregnated, addicted to heroin and planning a kidnapping, all because of a single puff.