I put this under "Politics", as politics in America has become definable as an unholy union of "Special Interests"(The Big players with so much greed and money, it's a tough call as to WHICH they have more of. Too much common sense of humanity? No worries.)
If you read the History,and especially if you take the time to DIG into it you'll find two things.
Hemp, highly regarded as a crop useful for many things, was prized as such for ALL of history until the folks pointed to above decided it threatened their precious bottom line...oh, and has little measurable THC- that is the active ingredient of:
Cannabis, which during most of the same period was touted for its diverse medical and health properties. (Is still considered as such in other more enlightened countries.
Big Pharma, Big Business, and the burgeoning "Corrections Industry" of the US busily disseminates propaganda and bogus "Bought-And-Paid-For-By-Your-Friend-The-Government" Science that is overwhelmingly trumped by-well. pretty much everyone else in History and the Scientific Community.
The deal is, if you keep "We The People" from ever READING the facts, then the Partnership of Money and Power can keep on doing "Business As Usual".
King George thought along similar lines...remember how well THAT worked out?