Again. The slave states, in proportion to their population, contribute nothing like an equal or equitable share to the aggregate of national wealth. It would probably be within the truth to say that, in proportion to numbers, the people of the free states have contributed ten times as much to the national wealth as the people of the slave states. Even for such wealth as the culture of their great staple, cotton, has added to the nation, the south are indebted principally, if not entirely, to the inventive genius of a single northern man.[26] The agriculture of the slave states is carried on with rude and clumsy implements; by listless, spiritless and thriftless laborers; and in a manner speedily to wear out the natural fertility of the soil, which fertility slave cultivation seldom or never replaces. The mechanic arts are comparatively dead among them. Invention is utterly dormant. It is doubtful whether either a slave or a slave holder has ever invented a single important article of labor-saving machinery since the foundation of the government. And they have hardly had the skill or enterprise to apply any of those invented by others. Who can estimate the loss of wealth to the nation from these causes alone? Yet we of the free states give to the south a share in the incalculable wealth produced by our inventions and labor-saving machinery, our steam engines, and cotton gins, and manufacturing machinery of all sorts, and yet say at the same time that we have no interest, and that there is "no propriety" in the constitutional guaranty of that personal freedom to the people of the south, which would enable them to return us some equivalent in kind. For the want, too, of an enforcement of this guaranty of a republican form of government to each of the states, the population of the country, by the immigration of foreigners, has no doubt been greatly hindered. Multitudes almost innumerable, who would have come here, either from a love of liberty, or to better their conditions, and given the country the benefit of their talents, industry and wealth, have no doubt been dissuaded or deterred by the hideous tyranny that rides triumphant in one half of the nation, and extends its pestiferous and detested influence over the other half.