Marijuana in the US:

At one point Hemp, the plant cannabis comes from, was a useful material. Used to create durable rope, twine, and cloth. It was also extremely prevalent in medicines for pain before aspirin was introduced. Everyone knew what Hemp was and its utility.

America in the 1900's saw two powerful rivals, agriculture and industry, faced off over several markets. When Rudolph Diesel produced his engine in 1896, he'd assumed it would run off of vegetable and seed oils, especially hemp, which is superior to petroleum.

It's a fuel source that can produced by plant matter instead of fossil fuels, can't get better than that. So enter Du Pont petrochemical company and Treasury Secretary Andrew Mellon. Mellon was a banker who took over Gulf Oil Corporation

Who also helped Du Pont secure a loan to take over General Motors. Du Pont has also developed a process to make trees into paper. In the 30s Ford figured out a way to turn Hemp into fuel and Du Pont was on the clock. They couldn't have Hemp as competition.

Ok, enter William Randolph Hearst. Hearst's company was a major consumer of the cheap tree-pulp paper that had replaced hemp paper in the late 19th century. The dude supplied trees to Du Pont to make paper and also really fucking hated people of color

And poor people as a matter of fact, but most of all he hated Mexicans. Pancho Villa's troops who smoked big gas took away 80,000 acres of his logging land. And Hemp's high quality cheaply made paper was replacing his shitty tree paper again.

Hearst had always supported any kind of prohibition, and now he wanted cannabis included in every anti-narcotics bill. Cannabis wasn't a Narcotic but with a friend as treasury secretary Du Pont and Hearst went to work changing that.

Around 1920 or so, a new word arose - "Marihuana". Through screaming headlines and horror stories,"marihuana" was blamed for murderous rampages by blacks and mexicans. Hearst continued to use his power of the press to impress on his readers the dangers of the "marihuana" plant.

Politicians connected with Du Pont started to lobby for a ban on Hemp citing how dangerous it was when really they were trying to defeat the competition. And although the medical community was against it Congress passed a bill virtually banning Hemp securing Du Pont's monopoly.

So bottom line is that when anything gets in the way of a private entity that has deep support in the Government it will disappear, regardless of how useful it may be to people. And if that means demonizing marginalized people, well that's just icing on the cake