It had everything to do with the king of yellow journalism newspapers not wanting competition for his yellow paper and the king of the new plastics not wanting competition with them: competition from hemp.

Kathleen Murphy wrote for the Washington Free Press 3 June 2009 about How Marijuana Became Illegal,

As the methods for processing hemp into paper and plastics were becoming more readily available and affordable, business leaders including William Randolph Hearst and DuPont stood to lose fortunes. They did everything in their power to have it outlawed. Luckily for Hearst, he was the owner of a chain of newspapers. DuPont’s chief financial backer Andrew Mellon (also the Secretary of the Treasury during President Hoover) was responsible for appointing Harry J. Anslinger, in 1931 as the head of the Federal Bureau of Narcotics and Dangerous Drugs.

Anslinger and Hearst made up whatever propaganda they thought might scare the public into supporting prohibiting hemp: Continue reading →