W. E. B. Du Bois, while at Harvard University, wrote his doctoral dissertation: The Suppression of the African Slave-trade to the United States of America 1638-1870. I had not known about this monograph until I picked up a compendium of his work at the George Hail Library here in Warren. I also discovered the webdubois.org website site that gives links to the various editions of the work online as well as much of what has been written about it since its publication in 1896. It is a masterful work, using facts to show how that “suppression” was, until the end, nonexistent. In the final chapter, he observes the catastrophic result of the failure of the men at the Constitutional Convention to address slavery at the end of the Revolutionary War: …there was never a time in the history of America when the system [of slavery] had a slighter economic, political, and moral justification than in 1787; and yet with this real, existent, growing evil before their eyes, a bargain largely of dollars and cents was allowed to open the highway that led straight to the Civil War.
Along with the nearly 200-page text of this piece, Dr. Du Bois also offers an impressive 
list of appendices. Appendix C includes a list of American vessels carrying Africans into slavery after the trade was “outlawed” in 1808; it goes on for many pages.
You can also see much more of Du Bois’ writings and correspondence via Credo at UMass Amherst. Born in Massachusetts in 1868 (just 3 years after the ratification of the 13th Amendment), he moved to Ghana late in life and died there at the age of 95, on the eve of the historic March on Washington in 1963.
WARREN MIDDLE PASSAGE PROJECT 