2727 B.C. — The Chinese document the use of cannabis as a medication.

1911 — South Africa becomes the first country to outlaw cannabis.

1913 — California is the first state to pass anti-marijuana laws.

1928 — Great Britain bans recreational marijuana use.

1936 — Reefer Madness is released in movie theaters.

1937 — The U.S. makes it illegal to possess pot.

1938 — Comedian Tommy Chong is born in Edmonton, Alberta, Canada.

1944 — A New York commission debunks the dangers of reefer.

1956 — The U.S. puts marijuana in the same drug class as heroin.

1965 — An estimated 1 million Americans admit to having tried ganja.

1967 — The Beatles urge pot use, singing, "I'd love to turn you on" and "Everybody smoke pot."

1972 — An estimated 24 million Americans admit to having tried marijuana.

1978 — Paramount Pictures releases Cheech & Chong's classic Up in Smoke.

1980 — Robert Platshorn is sentenced to 64 years in federal prison for smuggling pot.

1996 — California makes Mary Jane legal for medical use.

2003 — Canada becomes the first country to legalize marijuana.

2004 — Tommy Chong is released after nine months in federal prison for selling bongs.

2008 — Florida imposes tougher criminal penalties against marijuana growers.

2010 — The Sunshine State outlaws the sale of water pipes at head shops.

More on Marijuana:

Marijuana by the numbers

Medical marijuana: Taking a legal toke

Grow-house blues

Famous marijuana users