'Marijuana', literally 'the weed that intoxicates', was a mexican term adopted into the english language by
Harry Anslinger in the early part of the 20th cetury in order to provide a xenophobic label for the plant he sought to outlaw. The same plant that had had its extractums used on 3 generations of americans previously for medical and
recreational purposes.
Like cocaine, the early hysteria concerning marijuana usage was largely race-based, in both instances it was claimed that the drug made black slaves insolent (they'd walk on white men's shadows, look them straight in the eyes and refuse to go to the back of the trolley, that sort of evil insubordination), made decent white women look twice at blacks (see also jazz, hot clubs) and other such claptrap.