It provided the basis of wealth that put this country on the map as an economic power. If that industry failed the financial underpinnings that supported investment in other industry disappeared. The entire country depended on our primacy in producing cotton, and the reason we could produce it at such an advantage was free labor.
https://www.theatlantic.com/business/archive/2014/12/empire-of-cotton/383660/
By the time shots were fired on Fort Sumter in April 1861, cotton was the core ingredient of the worlds most important manufacturing industry. The manufacture of cotton yarn and cloth had grown into the greatest industry that ever had or could by possibility have ever existed in any age or country, according to the self-congratulatory but essentially accurate account of British cotton merchant John Benjamin Smith. By multiple measuresthe sheer numbers employed, the value of output, profitabilitythe cotton empire had no parallel.
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The industry that brought great wealth to European manufacturers and merchants, and bleak employment to hundreds of thousands of mill workers, had also catapulted the United States onto center stage of the world economy, building the most successful agricultural industry in the States of America which has been ever contemplated or realized. Cotton exports alone put the United States on the world economic map. On the eve of the Civil War, raw cotton constituted 61 percent of the value of all U.S. products shipped abroad. Before the beginnings of the cotton boom in the 1780s, North America had been a promising but marginal player in the global economy.
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Slavery stood at the center of the most dynamic and far-reaching production complex in human history. Too often, we prefer to erase the realities of slavery, expropriation, and colonialism from the history of capitalism, craving a nobler, cleaner capitalism. Nineteenth-century observers, in contrast, were cognizant of cotton's role in reshaping the world. Herman Merivale, British colonial bureaucrat, noted that Manchesters and Liverpools opulence is as really owing to the toil and suffering of the negro, as if his hands had excavated their docks and fabricated their steam-engines. Capital accumulation in peripheral commodity production, according to Merivale, was necessary for metropolitan economic expansion, and access to labor, if necessary by coercion, was a precondition for turning abundant lands into productive suppliers of raw materials.
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