Editor’s Note: Today’s post comes from contributing editor Dr. Seth Blumenthal, contributing editor and lecturer at Boston University.

In 1972 , spelling out marijuana’s gateway potential to Chicago Mayor Richard Daley, President Richard Nixon explained, “Once you cross that line, from the straight society to the drug society – marijuana, then speed, then it’s LSD, then it’s heroin, etc. then you’re done.” This stepping-stone rationale existed long before Nixon’s presidency, of course. Still, in the 1930s, years before the War on Drugs began under “Tricky Dick,” Harry Anslinger, the Federal Bureau of Narcotics director from 1931 to 1962, initially shied away from this causal relationship, preferring to target marijuana on its own.
But by 1951, Anslinger had embraced the gateway theory as well, finally acceding to the growing chorus that connected marijuana to eventual heroin addiction. Rather than credit (or blame) Anslinger and Nixon for this approach, the history of the gateway theory proves that the basic assumptions and mythologies surrounding marijuana were much larger than the drug itself, regardless of which drug it eventually connected to. Instead, the gateway theory represented the widespread concerns and sense of racism that shaped Americans’ association with drug use and addiction in the post-WWII era.