How 4/20 Became 420

Today is April 20. For some people, that's just the day after April 19. For others, it's the unofficial marijuana holiday. The story about how "420" became associated with pot has been clouded by an aromatic haze over the years. But one thing's for sure, it's not just an underground term anymore. The medical marijuana bill that was signed into law back in 2003 started in the California Senate as SB 420. We learn the history of how 4/20 became 420.