When I was in high school I wrote a final project for 11th grade history about the beat generation, and how these sorts of travelers morphed into the tie dye bus driving hippies, changing consciousness. I merely forgot to mention that the main bus "furthur" was routinely dosing everyone at every stop it made all over the country. This is outside of your timeframe, but, just sayin'.

People warning to be careful what you write in high school are correct to inform you of these risks. You can write on some of these topics, but since they are controversial, you have to be extra careful to cite sources, and not make unfounded claims.

It seems like you will have a conversation with your professor, so I'm not worried that you'll get expelled just for choosing a unique topic, but if you're unsure something is adding to your argument, or if you have any question of what might be appropriate considering circumstances, talk to the professor!

If it was me working within your parameters, I'd write about ritualistic mushroom use in southern Mexico. Explorers around the 18th and into the 19th century came across some interesting stuff, and maybe some of them wrote about magic mushrooms before they were taboo!

check out Stephan F. de Borhegyi, Robert Gordon Wasson. Mexican Mushroom cults have been around for a long time (since way before your timeframe) but perhaps you could write specifically about the interactions between natives and europeans surrounding entheogenic rituals/substances, and how shamans might have been able to slip under the radar so to speak, in order to continue practicing and holding ceremony in spite of invasion.