What invention most to make the shift to large plantations throughout the deep south profitable?
the textile mill
the mechanical reaper
the cotton gin
the sewing machine

The cotton gin was a major invention that helped to make the shift to large plantations throughout the Deep South profitable. The cotton gin was an invention that used a machine to remove the seeds and other plant pieces from cotton quickly so that lots of cotton could be processed quickly for sale. Previously this process had been done by hand and had been much slower than after the invention of the cotton gin. This invention led to a growth in plantations and the development of cotton and ultimately led to an increase in the use of slave labor as well.