The Supreme Court in March of this year [in Sonzinsky v. United States] sustained the constitutionality of the National Firearms Act, insofar as it related to the occupational tax.

[5][6][7] Interested parties write that the aim of the Act was to reduce the hemp industry through excessive taxation[8][9][10] largely as an effort of businessmen Andrew Mellon, Randolph Hearst, and the Du Pont family.

[8][11] Newspaper magnate William Randolph Hearst realized cheap, sustainable, and easily-grown hemp threatened his extensive timber holdings.

Mellon, Secretary of the Treasury and the wealthiest man in the US, invested heavily in the Du Pont family's new synthetic fiber, nylon, to compete with hemp.

The AMA proposed cannabis instead be added to the Harrison Narcotics Tax Act which would have been more efficient and created less burden on doctors.

[19] He stated that the claims about marijuana addiction, violence, and overdosage were not supported, and that the law should not burden further investigation into medical use.

Shortly after the 1937 Marihuana Tax Act went into effect on October 1, 1937, the Federal Bureau of Narcotics and Denver City police arrested Moses Baca for possession and Samuel Caldwell for dealing.

Judge Foster Symes sentenced Baca to 18 months and Caldwell to four years in Leavenworth Penitentiary for violating the 1937 Marihuana Tax Act.

After the Philippines fell to Japanese forces in 1942, the Department of Agriculture and the US Army urged farmers to grow fiber hemp.

"[23] In 1969 in Leary v. United States, part of the Act was ruled to be unconstitutional as a violation of the Fifth Amendment, since a person seeking the tax stamp would have to incriminate him/herself.

In addition, the Marihuana Tax Act of 1937 legitimized the use of the term "marijuana" as a label for hemp and cannabis plants and products in the US and around the world.

[28] In the years leading up to the taxation act, it was in common use in the United States, "smoked like tobacco", and called "ganjah", or "ganja".