The later half of the 19th Century saw a huge increase in cotton product. Far more than the antebellum years. This was before the age of mechanization and new cotton lands in the desert Southwest.
Almost all of the 19th century post Civil War cotton comes from sharecroppers, white and black. Note when the "area" (black line) of cotton grew in the 1920s. That was due mainly to Arizona and California irrigation. Once post WWII mechanization occurs, the area of cotton goes way down, but output remains steady.