I will take this opportunity to make some observations relevant to my statement that the United States became economically prosperous despite slavery and not because of it. Note that the article cited by Centrox says: " . . . by 1860 . . ." This is significant in regard to my statement. In 1788, when the first Washington administration began, cotton was not yet king. Eli Whitney patented the cotton gin in 1794, and it did not yet make cotton king. Tobacco continued to be the most valuable export crop from the United States, but that did not assure prosperity for the United States. That is because it did not generate foreign exchange which circulated in the economy. Southern planters, from long before the revolution, had a pernicious relationship with their London factors (agents). The factors sold the tobacco crops, and routinely lied about how much they had received. They then shipped goods to the American south that were either shoddy, or grossly over-priced. Precious little foreign exchange circulated in the economy as a result. George Washington, in the same year that he married Martha Dandridge Custis, ended his relationship with his London factor, whose house had served his half-brother Lawrence, and their father Augustus. He spent fifteen years paying off his debt to the London house, finally discharging the debt in 1774, just before the First Continental Congress was seated. He diversified his crops, growing wheat, rye, barley and oats, and running sheep and cattle on his land. He encouraged colonial industries, and began an early "buy American" movement.
(Washington did not own most of slaves on the estates he now managed. When he married Martha, he became the manager of the estates of her children--John Parke Custis, "Jacky," and Martha Parke Custis, "Patsy." He would not sell slaves, because it broke up families, although the law entitled him to do so as manager of his atep-children's estates. He was anxious not to create a situation in which Martha's life would be endangered upon his death, and so prepared a system whereby the slaves would all be provided housing, provender and clothing on the traditional basis. Those willing to work, and who worked well, were paid a small salary in addition. After his death, Martha manumitted the remaining slaves at Mount Vernon, but was not entitled to manumit the slaves from the Custis estates. Washington's estate paid pensions to former slaves until the 1830s. The only descendant of Martha and Daniel Parke Custis was George Washington Parke Custis, the son of Jacky. His daughter Mary married Robert Lee, and it was by that means that Lee, otherwise an almost impoverished engineer officer, acquired estates and slaves. Washington and his relationship to the London factors, as well as his efforts to deal with a very large slave population are well documented in the two great biographies, by Douglas Southall Freeman and James Thomas Flexner.)
In the early United States, foreign exchange which circulated in the economy derived chiefly from the grain and timber sold to European buyers, and produced largely in the northeast and in the mid-Atlantic states. There was another pernicious effect of slavery in the south. Small holders and small craftsmen had only local populations to sell to or to work for. Planters had slaves trained as blacksmiths, carpenters and joiners, and all the other myriad skills necessary to run estates. If you were a white man and a blacksmith, and you did not live in a city, you could limp along in poverty, or you could get out. Much of the migration from southern states was a product of small holders and small craftsmen looking for a better life. Additionally, of course, there were large areas in the American south where there were few slaves and few slave owners. This was why the northwestern counties of Virginia seceded from the commonwealth in 1861 and why the eastern counties of Tennessee attempted to do the same.
Another effect of the parasitic relationship between London and other European factors and American planters was the several, usually minor, political crises over the tariff. European ships could tie up at wharves on the extensive southern coastline, or run up the many rivers which flowed from the mountains to the sea. Southern planters were already getting screwed in the system whereby shps loaded their crops and delivered the goods ordered the previous year, and they didn't want to pay a tariff in addition to that, or to do the paperwork. The nullification crisis in Andrew Jackson's second term derived directly from the refusal of South Carolina to apply and collect the tariff. After Whitney's cotton gin, and especially after the War of 1812, cotton did become king. Small holding families, like that of Jefferson Davis, could now acquire cheap land in the "Deep South," and start up slave-driven cotton operations. It was from those operations that the millionaires mentioned in the work cited by Centrox acquired their fortunes. As cotton became king, the tariff and nullification faded from the American political landscape as important issues, but the acquisition of new land, and the spread of the slave culture took center stage. The political elites of the south were enraged when the new territories acquired during the Mexican war did not become slave states as per the Missouri compromise. Because of the three-fifths compromise, southern political elites wielded an inordinate power, out of proportion to the electorate in their congressional districts. When slavery did not spread to the New Mexico, Colorado, Arizona, Utah and California territories, they became alarmed. This was why John Floyd of Virginia, the Secretary of War, began shipping arms to southern armories in 1859, long before Lincoln became the Republican candidate in the 1860 election. The political elites of the south were spoiling for a fight. They started that fight, they got their collective military ass kicked, and they have been whining and lying about it ever since.
I stand by my statement that American economic prosperity was not founded on slavery, and that the United States became prosperous despite slavery, and not because of it. Slavery only became economically important from the 1840s onward, and only became a critical political issue after the Mexican War. People here will not accept simple-minded, intuitive statements about science, but they will swallow historical bullshit whole.
Of course, no personal reflection on Centrox is intended.