Author: USA TODAY

Twenty-nine states have legalized the use of medical marijuana and on top of that, nine states and Washington, D.C. have legalized recreational pot. But the question is, why was it illegal in the first place? The true history of “420” — the global code for marijuana — started with a treasure map, five teenage boys, a rogue Coast Guardsman and a lucky connection with the Grateful Dead. And, of course, some bud. Canna-sseurs worldwide have been celebrating April 20 (April 20 equals 420 in date form.) for decades, most of them not knowing why that date specifically was the chosen…