The Transatlantic Slave Trade of England and New England
The author below cites the report of the Marine Research Society of Salem, Massachusetts for the origin and perpetuation of African slavery in North America.  This raises the important question:  How does the American South receive the blame for African slavery in North America, yet it had nothing to do with its introduction and perpetuation?  It is an irony of history that the New England States which profited handsomely from the slave trade and perpetuation of African slavery would later prosecute a war for the extinction of what they had themselves wrought.
Bernhard Thuersam, Chairman
North Carolina War Between the States Sesquicentennial Commission
"The Official Website of the North Carolina WBTS Sesquicentennial"
The Transatlantic Slave Trade of England and New England:
“In the library of the State College of Raleigh, N.C., there is a notable book of some three hundred and fifty pages and forty-nine illustrations – the fifteenth publication of the Marine Research Society, of Salem, Mass., and published in Vermont – the title being: “Slave Ships and Slaving.”
The introduction was written by a British Navy officer, and the text is by George F. Dow. Within ten years after the discovery of America the Spaniards began the transport of Africans to work in their possessions, and all the maritime nations of Europe followed their example; and during the next two hundred and fifty years the English transported as many as all the countries put together.
They began in Queen Elizabeth’s time, kept is up in the next reign, and, in 1662, the Duke of York undertook to transport to the British Colonies three thousand slaves every year. Ten years later the King himself became interested and, under contract, England got from Spain the exclusive right to supply the Spanish colonies; and the King of England and the King of Spain each received one fourth of the profits.
Between 1680-1688 England had two hundred and forty-nine slave ships; from 1713, for twenty years, 15,000 slaves were annually brought to America. In 1786, England brought over 97,000 slaves.  During eleven years, 1783-93, Liverpool owned eight hundred and seventy-eight vessels in this trade, and imported many thousands of slavers in the West Indies. They were worth some 15,000,000 pounds of that period; equal to about $150,000,000 now.
While Liverpool was the chief port for this trade, Bristol was a close second. Then, over here, New England was not slow.  Massachusetts started in 1638. However, Rhode Island became the rival of Liverpool. Ten pages of this volume are devoted to the operations of Rhode Island. There nearly every one was interested…[and by] 1750, “Rum was the chief manufacture of New England.” About 15,000 hogsheads of molasses were annually converted into rum in Massachusetts alone.   The number of stills in operation was almost beyond belief [and] in Newport there were no less than twenty-two.”
With rum they purchased Negroes in Africa; these were exchanged for molasses in the Caribbean Islands and South American, and the molasses was brought to the New England stills; and so the profitable business was carried on in a circle to the extent beyond ordinary imagination!
It was the very basis of New England’s prosperity.  At Newport, Bristol and Providence, some of the most respectable and wealthy merchants were engaged in the trade.  Even preachers and philanthropists were advocates. “One elder, whose ventures in slaving had usually turned out well, always returned thanks on the Sunday following the arrival of a slaver that the Africans could enjoy the blessing of a Gospel dispensation.”
The Southern colonies had no ships, nor any molasses. They were not in the trade. However, the British Slaving Company, in which the King of England was partner and in duty bound to supply the needs of the colonies as particularly required by Good Queen Anne. The Colonies were forbidden to manufacture, and their products were required to be shipped to England, where they were exchanged for British goods. So the more slaves making products, the more goods the Colonies bought in England.
At length Virginia forbade any more importation [of slaves] but the King annulled that Virginia law. In Jefferson’s draught of the Declaration of Independence he denounced the King most severely for annulling these prohibitions. However, in 1774, importations [of slaves] were forbidden by the people of North and South Carolina, and there were no importations until 1803, when South Carolina opened her ports for four years. 
Great Britain abolished the [slave] trade in 1807, just as the Congress of the United States did. After a few years, other countries followed our example: Spain in 1820, Portugal in 1830; but the trade between Portuguese Africa and Brazil did not cease until Brazil, in 1888, put a stop to it. 
The Southern Colonies had no ships engaged in this trade, nor any molasses or rum, but, as the matter worked out, those States were the greatest sufferers in the end. Since 1800, the labor of Africans in the South have largely supplied the world with cotton.
That this volume was prepared by the Marine Research Society of Salem, Mass., speaks well for New England, and it should be in every library in the South.”
(The Slave Trade, Captain S.A. Ashe, Confederate Veteran, December, 1930, page 457)