The production and marketing of hemp suffered a rapid decline after the Second World War. This decline is due to a combination of factors, related to both political lobbying and the strong industrial development that characterised the 20th century. Hence, the lobbying, criminalisation and demonisation of cannabis are de facto a recent invention, originating in the United States in the 1930s.

1937: Marijuana Tax

The prohibition of hemp was finally sanctioned in 1937 with the so-called Marijuana Tax Act and further strengthened in the 1950s. Subsequently, other countries around the world also gradually prohibited hemp production, exchanging it for marijuana, inducing very severe penalties for possession and cultivation and equating hemp with hard drugs.

Almost at the same time as the Marijuana Tax Act was passed, the journal Popular Mechanics published a very important article in which it emphasised the economic potential of hemp, calling it 'the plant worth a billion'. This strong claim is supported by the considerable improvements made to the husker by George Schlichten, and even though there were already several similar machines on the market, Schlichten's husker was the only one that allowed the stem to be separated from the fibre, thus modernising the process of textile production without an additional demand for labour, but guaranteeing a considerable prospect of growth. The article also emphasises the different uses of hemp, stating that over 25,000 different products can be created from it and that the textile sector alone, which was very important at the time, has at least 5,000 products in use, from sails for boats to laces for shoes.

One product that perfectly sums up the Popular Mechanics newspaper's claims is Ford's Hemp Body car, made entirely from sustainable soya and hemp materials and fuelled by hemp ethanol, obtained from the plant's seeds.

It is clear, however, that in the short to medium term, the two sectors that could have benefited most from the industrial development of the decorticator are the textile and paper industry, as the production cycle would have been considerably speeded up and the by-product of the fibre, i.e. the woody part consisting of about 80% cellulose, could be used for paper production.

Popular Mechanics, 1938, Link

In fact, it is precisely for these reasons related to so many different uses of cannabis that the American capitalist world, represented primarily by Hearst [1], the paper and publishing magnate, and Rockefeller, petrochemical entrepreneur and investor in what will shortly be known as big pharma, began to view hemp with disdain and tried, some directly and some less directly, to block its expansion.

This lobbying was also supported by remarkable industrial, petrochemical and pharmacological developments. In the early 1900s, the Du Pont brothers patented several petroleum derivatives for civil use, such as nylon, naflon, lycra and teflon. These derivatives could also be used in textiles (synthetic fibres) but also in the food industry and this multiplicity of sectors allowed the Du Pont brothers to become the world leader in petrochemistry [2]. On the pharmacological side, on the other hand, the invention of aspirin was only the first step towards the development of drugs that were increasingly synthetic (and also cheaper) than the drugs of natural origin that had been used until then.

But perhaps the most relevant reason for understanding why textile hemp is not used nowadays comes from another fibre plant, namely cotton. ‍

The role of cotton

Cotton is a vegetable fibre, composed of 95% cellulose, which after flowering leaves a white coloured fruit, called cotton wool, full of tiny hairs. Once harvested and processed, the bale is transformed first into yarn and then into textiles, giving rise to the cotton we all know and which is widely used in our daily lives. There are several points that have worked in cotton's favour, allowing it to de facto increasingly replace hemp.

First and foremost, the low cost of labour (also linked to slavery in the USA in particular), together with the increase in mechanisation in agriculture, considerably increased the demand for and use of cotton. In fact, until around 1600, cotton was considered a luxury product as it was imported from the USA and other British and Spanish colonies.

The final victory came with the invention of the mechanical loom and the steam engine, which enabled the process to be speeded up as the mechanical harvesting of cotton was easier than that of hemp, and the low labour costs also played an important role in the final price of the cotton fabric.

Last but not least, from an agricultural point of view, cotton has a lower yield per hectare than hemp but requires considerable amounts of water, fertilisers and pesticides, as the soil remains rather depleted of nutrients after harvesting. The demand for these additional chemicals needed to optimise the growth of cotton also opens up a new market segment for the petrochemical industry [3].

Role of paper

A further important aspect that has led to a drastic decrease in the use of industrial hemp is related to paper production. In fact, the use of hemp for paper is almost as old as its use for textiles: Gutenberg's bible, America's Declaration of Independence, as well as the canvases of the most prized works of art, were written on hemp paper, which is a rough and very durable paper.

Paper production is obtained from a by-product of the hemp fibre, hemp hemp, which, depending on the length of the fibre, can be used for the production of more or less valuable paper. In addition, hemp paper does not need any further chemical bleaching processes, is stronger and more durable than cellulose paper and can also be produced from recycled hemp cloth and ropes [4].

However, at the height of industrial development in 1900, the production of hemp paper was still manual, and was therefore very expensive and in contrast to the publishing demand of the time, driven mainly by the entrepreneur and politician William Randolph Hearst, who needed a lightweight, low-strength and above all cheap paper for the production of disposable daily newspapers. Due to its very strong fibre, hemp could not be processed mechanically and therefore cellulose fibre, which requires a mix of chemical solvents for processing and therefore de facto convenient for the chemical industry, proved to be more suitable for this purpose (patience if centuries-old trees were cut down!).

Cannabis associated with violence and crime

The combination of the above, coupled with strong immigration from Mexico, allowed the use of hemp to be coupled with marijuana, creating media campaigns, supported by numerous Hearst newspapers, and racist propaganda linking the use of hemp to violence and addiction. Even Hollywood engaged in this veritable hemp-hunting, with a series of films aimed at changing public opinion on the matter, reporting that hemp use causes violence, mental disorder and above all addiction (things that have obviously been disproved over the years, in fact a study shows that cannabis containing TCH is only 9th in terms of addictiveness, while alcohol - permitted and legal in many western as well as eastern countries - is 3rd). The film Referred Madness - demonising cannabis as a highly addictive drug that caused mental disorder and violence, offers a completely distorted view of this plant that has accompanied man sapiens for the last 10,000 years (at least!).

However, these different historical aspects led to the fact that hemp was banned completely almost worldwide, both for industrial and for galenic and recreational cultivation. Only a few countries continued to cultivate it for industrial purposes, mainly China (in fact, the largest exporter to date) and France, albeit in a very limited way.

The Return of Cannabis

After a long period of prohibition on the entire Cannabis Sativa plant, hemp production has resumed in recent years and is mainly cultivated for food and industrial uses, including paper, clothing, ropes, building materials, biofuels and cosmetics. In addition, hemp is re-becoming an excellent alternative to many natural and synthetic textiles, mainly due to its sustainability in cultivation

References and insights:



[3] Hemp, An Incredible Story, (2019), M. Gracis



[F1] Crime Scene Do Not Cross Signage, Kat Wilcox, Pexels

[F2] Popular Mechanics, 1938, Link

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