The United States remained the dominant cotton-producing nation until well into the twentieth century.  Soil depletion undermined the productivity capacity of cotton's traditional heartland in the southeastern seaboard, and the center of cotton production thus shifted westward toward Texas.  Despite the beginnings of these and other ecological problems, as of the late 1920s the US still produced 50% of the world's cotton.  By then, however, modern agricultural techniques were increasingly widespread around the globe, and the position of the US began a long decline that continues to the present.

As it did with many other agriculture commodities, the large-scale mechanization of cotton farming arrived in the middle of the twentieth century.  It began in the United States as cotton farmers and interests tried to maintain American cotton's dominance.  From there, the techniques and technology spread around the world, sometimes opening areas to cotton production that had been hitherto environmentally unfit for cotton (such as the case of Australia), and dramatically changing it in areas in which cotton had already been grown (such as the case of the Soviet Union.)  The so-called green revolution of the postwar era had a huge impact on cotton yields; the United Nations collected statistics that indicated that cotton production worldwide was at about four million metric tons in the late 1940s, but had increased more than four times that amount to over eighteen million metric tons by the 1990s.

In turn, along with mechanization and new chemical combinations of fertilizer and pesticides, water management opened up millions of acres of formerly arid lands to cotton cultivation.  The agricultural historian Helen Wheatley noted that the Australian cotton industry had been extremely small well into the twentieth century, but following the importation of American water-management techniques and technologies, it rapidly grew after the 1940s.  By the end of the century, Australia was behind only the US and Pakistan in exporting to the Asian textile industries

Of course, as was the case with the advent of industrialized manufacturing over a century earlier, the new patterns of industrialized production may have spelled increased efficiency and opportunities for certain individuals and groups, but they were not a straightforward case of “progress.”  Small farmers, whether they were financially independent or sharecroppers, were steadily pushed out of cotton cultivation as larger and larger commercially-owned farms proved that industrial production needed to employ economies of scale.  Simultaneously, governments became increasingly involved in the minutia of the cotton industry (as they were in virtually every sector of agriculture.)  In the Soviet Union, vast resources were expended organizing industrial cotton production on a colossal scale, a task accomplished with characteristic Soviet inefficiency and blundering.  In the US, the federal government supported the creation of large farms through tax breaks and international trade agreements that opened even more foreign markets to US cotton.

Even as small farmers were sidelined by the growth of huge commercial agricultural concerns, the ecological impact of industrial farming became increasingly evident.  As water management schemes diverted rivers to irrigate deserts and chemical pesticides fought back pests, once-abundant resources began to vanish.  Due largely to the essentially limitless market for raw cotton, every available water source was ruthlessly exploited to increase the areas of cotton production in places as far-flung as California and Australia.  Especially in the latter case, the absolute capacity of water resources was soon reached – it simply did not rain enough and the aquifers were not deep enough to quench the thirst of the Australian cotton industry.  Likewise, in numerous areas pesticides ended up poisoning water sources and rendering once-fertile land unfit for farming.

The medium and long-term consequences of cotton's industrialized production is not yet entirely clear.  At times, as in a large-scale eradication campaign waged against the cotton-killing boll weevil in the US in the 1970s, initiatives to improve cotton yields backfired.  In the case of the anti-weevil campaign, pesticides killed the weevils in certain areas, but other insects thrived after their predators had been killed off as well, and the cotton crops ended up being devastated.  Other cases are more ambiguous; as of 2003, fully 80% of all cotton grown in the United States is genetically modified.  Genetic modification has not proven to be pernicious, but neither has it “proven” to be entirely safe.  The consequences are simply not yet clear.

Cotton in the contemporary world follows several of the prevailing patterns for global trade more generally.  Whereas there had been international bodies that sought to regulate its exchange during the Cold War, in the post-1989 environment cotton is traded globally without the oversight of a specific governing body.  The US remains a major producer and manufacturer of cotton, but by the 1990s China had surpassed the US in terms of both production and manufacturing.  Everywhere, cotton's life-cycle remains fundamentally industrial: it is overwhelmingly grown on large farms, harvested using advanced mechanized equipment, and distributed to markets thousands of miles from its various points of origin.  And, as at least one historian has pointed out, the semi-official uniform of the late twentieth and early twenty-first century is the t-shirt and blue jeans; we march into the future garbed in industrial cotton.

Thus, it might not be too much to claim that cotton is one of the truly global factors in the history of human civilization.  This is not, of course, to argue that people who did not, or do not, have access to or prefer cotton over other fabrics are uncivilized, it is simply to note that cotton has been used across the globe as one of the favored fabrics of numerous societies since they slowly began to take up agriculture and create settlements after the last ice age.  If anything, it is the universality of cotton that makes it so difficult to pin down; it has been part of essentially all the major changes that societies have undergone, from settlement itself to the growth of regional then global trade, slavery, freedom, industrialization, mechanization, and modern globalization.