Cannabis’ journey toward legalization in the US is helpful in understanding the shift taking place around the 420 holiday. Although legal marijuana in the US owes an unpayable debt to San Francisco—to the struggles and the activists living in the city, those affected by AIDS and the counterculture warriors who laid the groundwork for the first legal cannabis in the nation—the historic relationship between cannabis and the “official” San Francisco, the civic leaders and the electeds, is at best uneasy and erratic.
https://cannabisnow.com/the-4-20-holiday-whos-it-actually-for/