Marijuana's history in the U.S. is complicated. Colorado Public Radio reporter Ann Marie Awad explains how cannabis became illegal -- and how we got from there to the start of the modern legalization movement. If nothing else, listen just to hear the phrase "jazz cigarettes."

The episode includes stories about Harry Anslinger, an early anti-marijuana crusader; how Richard Nixon pushed to classify weed alongside harder drugs; how AIDS activists in California paved the way for medical marijuana. Interviewees include drug historians Emily Dufton and Adam Rathge.

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