Rep. Robert L. Doughton of North Carolina introduced the Act in Congress on April 14, 1937 to criminalize the recreational use of marijuana through prohibitive taxation. The bill was the brainchild of Commissioner Anslinger who later testified before Congress in support of the bill. Congress held only two hearings to debate the merits of marijuana prohibition. The hearings totaled just one hour... Federal witness Harry Anslinger testified before the House Ways and Means Committee that "this drug is entirely the monster-Hyde, the harmful effect of which cannot be measured." He was joined by Assistant General Counsel for the Department of the Treasury, Clinton Hester, who affirmed that the drug's eventual effect on the user "is deadly." These statements summarized the federal government's official position and served as the initial justification for criminalizing marijuana smoking...

The American Medical Association (AMA) represented the lone voice against marijuana prohibition before Congress. AMA Legislative Counsel Dr. William C. Woodward testified, "There is no evidence" that marijuana is a dangerous drug. Woodward challenged the propriety of passing legislation based only on newspaper accounts and questioned why no data from the Bureau of Prisons or the Children's Bureau supported the FBN's position. He further argued that the legislation would severely compromise a physician's ability to utilize marijuana's therapeutic potential. Surprisingly, the committee took little interest in Woodward's testimony and told the physician, "If you want to advise us on legislation, you ought to come here with some constructive proposals ... rather than trying to throw obstacles in the way of something that the federal government is trying to do."

...After just one hearing, the Ways and Means Committee approved the "Marihuana Tax Act." The House of Representatives followed suit on August 20 after engaging in only 90 seconds of debate. During this abbreviated floor "discussion," only two questions were asked. First, a member of congress from upstate New York asked Speaker Sam Rayburn to summarize the purpose of the bill. Rayburn replied, "I don't know. It has something to do with a thing called marijuana. I think it is a narcotic of some kind." The same representative then asked, "Mr. Speaker, does the American Medical Association support the bill?" Falsely, a member of the Ways and Means Committee replied, "Their Doctor Wharton (sic) gave this measure his full support ... [as well as] the approval [of] the American Medical Association." ...Following this brief exchange of inaccurate information, the House approved the federal prohibition of marijuana without a recorded vote.