"The invention of the cotton gin", said Tompkins, "... Before 1860 ... was nearer anything else than a blessing. It was primarily responsible for the system of slavery.... Cotton ... in its manufacture ... is the life of the South, but we could probably have done as well without it until we began to manufacture it."[74] Not too dogmatic is the opinion expressed that "It seems as clear as day that ... cotton made the South a free trade section and the North protective; cotton lured the South back to slavery;[75] cotton drove the South to an extreme States-rights position ... and cotton at last drove the South to translate extreme States-rights into the terms of Secession...."[76] And with regard to internal policy, "Perhaps the most striking economic change that the new industry (cotton culture) effected in the South after the reintroduction of slavery was the speedy abandonment of manufactures ... what was the use of nerve-racking investment in elaborate and costly machinery when a land-owner could reap ten per cent net profit from a few negroes and mules and a bushel or two of the magical cotton seed? and yet the South had unusual manufacturing facilities ... manufacture soon fell into decay; the Piedmont region being still dotted with the moldering ruins of iron works and other mills that bear witness to the overwhelming power of the new agricultural absorption."[77] It has been observed that the social difference between North and South before the war, so often looked upon as something existing as of itself apart, as a matter of fact may be fully accounted for simply by the institution of slavery, which arrested development on Southern soil of the industrial type of American civilization.[78]