'Paradoxically, the cotton gin, a labor-saving device, helped preserve slavery in the U.S. Before the 1790s, slave labor was primarily employed in growing rice, tobacco, and indigo, none of which were especially profitable any more. Neither was cotton, due to the difficulty of seed removal. But with the gin, growing cotton with slave labor became highly profitable – the chief source of wealth in the American South, and the basis of frontier settlement from Georgia to Texas. "King Cotton" became a dominant economic force, and slavery was sustained as a key institution of Southern society.'