4/20 grew from humble roots to marijuana’s high holiday The Associated Press420 origins traced to San Rafael’s ‘Waldos’ KTVU FOX 2 San Francisco420 History: How April 20 Became Known as ‘Weed Day’ | TIME TIMECannabis drinks allow people to go “Cali Sober” on 4/20 AxiosGrassroots Support for Legalizing Marijuana Hits Record 70% news.gallup.com