November 23, 1919: Mescaline is first isolated and identified by Dr. Arthur Heffter.

November 24, 1976: Federal Judge James Washington rules that Robert Randall's use of marijuana constitutes a "medical necessity."

November 28, 1993: Reuters reports that Colombia's prosecutor general Gustavo de Greiff said the war on drugs has failed and Colombia should legalize cocaine and marijuana trafficking because the United States and Europe are decriminalizing consumption.

November 27, 2001: Dr. Francisco Moreno of the University of Arizona at Tucson begins dosing subjects who suffer from obsessive-compulsive disorder with psilocybin, the active ingredient in mushrooms. The government-approved research is funded by the Multidisciplinary Association for Psychedelic Studies and the Heffter Research Institute.

November 26, 2002: The Winston-Salem Journal (NC) reports that more than 30 drug defendants in Davidson County have had charges dismissed or convictions overturned since the officers investigating their cases were charged with distributing drugs and planting evidence.

November 29, 2004: In the US Supreme Court, oral arguments are heard in the Gonzales v. Raich medical marijuana case.