The military also got into the act, and asked that marijuana be prohibited.
The American Medical Assn. objected to the passage of the Marijuana Tax Act in 1937, which prohibited hemp farming.

In 1992, 330,000 arrests for cannabis possession. Dunno current figures.

I saw figures that marijuana was a major crop in some states and provinces; it grows well in much of North America. Here in Calgary, it is grown commercially under lights. Lots of busts, but the growers (who have rented the house) just disappear, a paid tender arrested.