Dear Agent ____,

Please prepare all cases in your jurisdiction involving musicians in violation of the marijuana laws. We will have a great national round-up arrest of all such persons on a single day. I will let you know what day.

—Harry Anslinger, Commissioner of the Federal Bureau of Narcotics, in a letter dated October 24, 1947, to all field agents. As quoted by Charles Whitebread in "The History of the Non-Medical Use of Drugs in the United States"