They would use “420” as a code for meeting up and embarking on their search. Though they never found the crop, the term stuck, and “420” became synonymous with cannabis culture. The term spread throughout the 70s and 80s, gaining popularity among cannabis enthusiasts and eventually becoming a symbol for the fight for legalization. In the 1990s, the Grateful Dead began using the term in their concerts, further cementing its place in cannabis culture.