Here is the story of cannabis, aka marijuana. Today it is illegal in most places, but that likely is to soon change, especially after people watch this video.
Sources: Erich Goode and Nachman Ben-Yehuda. Moral Panics: The Social Construction of Deviance
Martin Booth. Cannabis: A History
Martin A. Lee. Smoke Signals: A Social History of Marijuana: Medical, Recreational, and Scientific.
Grass: The History of Marijuana.
Bruce Barcott. Weed the People: The Future of Legal Marijuana in America.
John Charles Chasteen. Getting High: Marijuana through the Ages
