1970 CE
The Controlled Substances Act classifies mescaline as a Schedule I controlled substance

The United States passes the Controlled Substances Act, which classifies mescaline as a Schedule I controlled substance, effectively making peyote illegal in the U.S. However, this law allowed the use of peyote and mescaline for religious purposes (the Native American Church was exempt from the restrictions of this Act).

Source: Olive, M. F., & Triggle, D. J. (2007). Peyote and Mescaline. Infobase Publishing.

Drugs: Peyote (mescaline)
Regions: USA (United States of America)
Topics: Prohibition