Oh, but you missed the best part. Here is some of the actual Congressional testimony of one Harry J. Anslinger, in 1937:

"Marijuana is the most violence-causing drug in the history of mankind... Most marijuana smokers are Negroes, Hispanics, Filipinos and entertainers. Their Satanic music, jazz and swing, result from marijuana usage. This marijuana causes white women to seek sexual relations with Negroes."