From Drug War Rant's article entitled 'why is marijuana illegal?'
"Anslinger was an extremely ambitious man, and he recognized the Bureau of Narcotics as an amazing career opportunity -- a new government agency with the opportunity to define both the problem and the solution. He immediately realized that opiates and cocaine wouldn't be enough to help build his agency, so he latched on to marijuana and started to work on making it illegal at the federal level.
Anslinger immediately drew upon the themes of racism and violence to draw national attention to the problem he wanted to create. He also promoted and frequently read from "Gore Files" -- wild reefer-madness-style exploitation tales of ax murderers on marijuana and sex and... Negroes. Here are some quotes that have been widely attributed to Anslinger and his Gore Files:
"...the primary reason to outlaw marijuana is its effect on the degenerate races."
"Marijuana is an addictive drug which produces in its users insanity, criminality, and death."
"Reefer makes darkies think they're as good as white men."
"Marihuana leads to pacifism and communist brainwashing"
"You smoke a joint and you're likely to kill your brother."
"Marijuana is the most violence-causing drug in the history of mankind."