Andeerz, sorry about the "And read three or four times too" comment there, that was nastier on my part than I meant to be.
Yeah, even at the beginning of the 20th century it was seen as a ridiculous imposition for government to forbid citizens from consuming drugs. The first restrictions in the U.S. were actually just extreme taxes instead of making the consumption of drugs outright illegal. From reading the history it seems to me like it was Prohibition which initially gave the impetus to start restricting the use of other drugs.
It may have stemmed in part from the fact that pharmaceuticals were
completely unregulated around 1900; an apothecary could sell just about anything it wanted to without any labeling or quality controls. There's the figurative expression a "snake oil salesman" today but they actually did sell snake oil back then, even in mainstream drug stores. You can look in old newspapers and magazines on Google News and Google Books and see advertisements for it and you can see it in pharmacy catalogs. But journalistic investigations found that what was sold usually wasn't actual oil made from snakes, it was usually some kind of vegetable oil with cayenne pepper added to it to give it a "bite" and make it seem like what people would expect snake oil to be like.
Actually, until fairly recently it was believed that smoking was beneficial to your health.
No kidding, there were actually
medicinal cigarettes sold back then - to treat asthma of all things. I've even come across mention of an indication that the phrase "blow smoke up your ass" was derived from an actual medical practice, though I can't find the reference now.
They really liked shoving things up your ass back then; enemas made from some kind of booze were a regular prescription and before they invented rubber tubing to do gavage / tube feeding of patents who couldn't eat or swallow they would literally feed you by giving you a chicken soup enema. I am so glad that I live in the 21st century.