January 16, 1919: The 18th Amendment (alcohol prohibition) is declared ratified and is scheduled to take effect in one year.

January 16, 1920: At midnight, the 18th Amendment becomes law, making alcohol illegal.

January 12, 1929: The Porter Narcotic Farm Act is passed, establishing the first two narcotics hospitals for addicts in federal prisons in response to addicts' crowding.

January 14, 1937: A private federal cannabis conference takes place in room 81 of the Treasury Building in Washington, DC, leading to enactment of federal marijuana prohibition later that year.

January 15, 1963: President Kennedy establishes the Advisory Commission on Narcotic and Drug Abuse, with Judge E. Barrett Prettyman as chair.

January 16, 1980: Paul McCartney is arrested by Japanese customs officials at Tokyo International Airport when they find two plastic bags in his suitcases containing 219 grams of marijuana (approximately 7.7 ounces). Concerned that McCartney would be refused a US visa under immigration laws if convicted and be unable to perform in an upcoming Wings concert in the US, Sen. Edward Kennedy calls first secretary of the British Embassy D.W.F. Warren-Knott on January 19. McCartney is released and deported on January 25.

January 18, 1990: Mayor Marion Barry of Washington, DC, is arrested after hidden cameras record him smoking crack cocaine with ex-girlfriend Hazel Diane "Rasheeda" Moore in her room at the Vista Hotel.

January 15, 1997: Milahhr Kemnah, an AIDS patient visiting the Cannabis Cultivators Club in San Francisco, becomes the first person to buy medical marijuana in California following passage of Proposition 215.

January 12, 2001: Salon.com reports that the nephew of Attorney General-designate John Ashcroft received probation after a felony conviction in state court for growing 60 marijuana plants with intent to distribute the drug in 1992. This is a lenient sentence, given that these charges often trigger much tougher federal penalties and jail time. Ashcroft was the tough-on-drugs Missouri governor at the time.

January 15, 2002: The Associated Press reports that a federal appeals court ruled that, in Idaho, marijuana users can drive legally as long as their driving isn't erratic and they can pass a field sobriety test. A three-judge panel of the San Francisco-based 9th US Circuit Court of Appeals wrote that while it is illegal to drive under the influence of alcohol or narcotics, Idaho law doesn't list marijuana as a narcotic.

January 14, 2003: A high profile pain prosecution ends with a whimper when California prosecutors dismiss all remaining charges against Dr. Frank Fisher.