the cotton gin caused massive growth in the production of cotton in the United States, concentrated mostly in the South. Cotton production expanded from 750,000 bales in 1830 to 2.85 million bales in 1850. As a result, the region became even more dependent on plantations that used black enslaved labor, with plantation agriculture becoming the largest sector of its economy. While it took a single laborer about ten hours to separate a single pound of fiber from the seeds, a team of two or three enslaved people using a cotton gin could produce around fifty pounds of cotton in just one day. The number of enslaved people rose in concert with the increase in cotton production, increasing from around 700,000 in 1790 to around 3.2 million in 1850. The invention of the cotton gin led to increased demands for enslaved labor in the American South, reversing the economic decline that had occurred in the region during the late 18th century. The cotton gin thus "transformed cotton as a crop and the American South into the globe's first agricultural powerhouse". Because of its inadvertent effect on American slavery, and on its ensuring that the South's economy developed in the direction of plantation-based agriculture (while encouraging the growth of the textile industry elsewhere, such as in the North), the invention of the cotton gin is frequently cited as one of the indirect causes of the American Civil War. Modern cotton gins In modern cotton production, cotton arrives at industrial cotton gins either in trailers, in compressed rectangular "modules" weighing up to 10 metric tons each or in polyethylene wrapped round modules similar to a bale of hay produced during the picking process by the most recent generation of cotton pickers. Trailer cotton (i.e. cotton not compressed into modules) arriving at the gin is sucked in via a pipe, approximately in diameter, that is swung over the cotton. This pipe is usually manually operated, but is increasingly automated in modern cotton plants. The need for trailers to haul the product to the gin has been drastically reduced since the introduction of modules. If the cotton is shipped in modules, the module feeder breaks the modules apart using spiked rollers and extracts the largest pieces of foreign material from the cotton. The module feeder's loose cotton is then sucked into the same starting point as the trailer cotton. The cotton then enters a dryer,