In 1929 the American Antiquarian Society published an eighty-three-page manuscript that describes commercial transactions for slaves, ivory, and gold on the Gold and Slave Coasts from 1789 to 1792. George Plimpton owned this manuscript. As it includes a slave-trading ledger of the schooner Swallow, Plimpton entitled the manuscript “The Journal of an African Slaver.” The “journal” is one of the few published documents in the English language that specifies financial transactions for slaves between European and African traders on the coast of Africa during the late eighteenth century.In his four-page introduction to the journal Plimpton stated that:The name of the ship engaged in the traffic was the schooner ‘Swallow,’ Capt. John Johnston, 1790-1792. There is a reference to a previous voyage when ‘Captain Peacock had her,’ also some abstracts of accounts kept by Capt. David McEleheran in 1789 of trade in gold, slaves and ivory on the Gold Coast. None of these names can be identified as to locality, and there is, of course, the possibility, especially taking into consideration the English nature of the cargo bartered, that the vessel was an English slaver.The journal was included with some mid-nineteenth century South Carolina plantation accounts when it was purchased at an auction in New York, thus suggesting to Plimpton that the journal's author was perhaps a “South Carolinian who made this trip to Africa.”In this research note I will identify the various vessels and traders mentioned in this manuscript by referring to the data-set I have assembled from other sources concerning the slave trade during this period. We will seethat Plimpton's “journal” is a set of account books owned by the Gold Coast agents of London and Havre merchant William Collow. I then will discuss the importance of Collow as a merchant and shipowner in the late eighteenth-century British slave trade.