Nice piece over here at ZME which documents some historical medicines that contain drugs that are far from legal nowadays. From Bayer's Heroin to Benzedrine Inhalers, it certainly seems odd that these were once marketed openly – being culturally acceptable.
You could use this feeling of oddness to support the widespread view that our generation's culture is closer to enlightenment – to absolute truth and wisdom – than our predecessors; alternatively you could use it as a marker to that what we take for "acceptable" "how things are" and so on, is subject to change. And thus a call for humility.
I know where my money is.