United States cotton production and area 1790-1988
The mechanical cotton gin's invention in 1793 revolutionized the U.S. cotton industry, which grew exponentially in the early 19th century. Cotton was the U.S.' primary export in these years, and its production was driven by slave labor in the southern states (particularly South Carolina). For the first time, output exceeded one million tons in 1859, and again in 1861, however, the disruption of the American Civil War caused cotton output to drop by over 93 percent in the next three years, to just 68 thousand tons by 1864. Production resumed upon its previous trajectory following the war's end, and many of the former-slaves forced to work on cotton plantations continued to work in the cotton industry, but as sharecroppers who worked the land in exchange for a share of the harvest, as well as housing and facilities (this was similar to tenant farming, although sharecroppers received a smaller share of the crop and had fewer legal protections).