Not the webpage documenting the perjury in front of congress - and while I can’t find the best presentation of these facts, I did find this here:
This was the final salvo in the battle for control of America’s paper production. Randolph Hearst the newspaper and lumber baron, reportedly feared a major loss of revenues and aligned with his son-in-law Harry Anslinger, an opportunistic minor government official. Anslinger hated Mexicans and blacks, and demonized cannabis as “marijuana”—a denigrating reference to its Hispanic name.
He rallied support against this “marijuana” drug being imported from Mexico and the Caribbean, so that many of the legislators who voted for his bill did not realize that they were criminalizing the hemp plant grown in their own gardens and communities. To strengthen support, Anslinger and his cronies suborned perjury to the US Congress about the American Medical Association (AMA) position. In 1937, the AMA actually opposed Prohibition, regarding cannabis as a safe drug.