[dragonwriter]

> 420 was the California Bill for medical marijuana legalization

“420” was established term for weed before SB 420 of 2003 was introduced; the slang didn't come from the bill but the bill was introduced on a timing to exploit the slang.

Also, Medical Marijuana was legalized by Prop 215 of 1996, SB 420 of 2003 was a measure to revise some provisions of the regulatory regime.