In Washington Irving's narrative sketch, Tom Walker "resolutely refuses" to become involved in "black traffic," otherwise known as the slave trade.
After his wife's death, Tom Walker is eager to gain the promised treasure, so he meets the black man in the woods one night. At first, the "black man" is circuitous, but eventually he and Tom begin to haggle about their deal. When the Devil suggests that Tom "fit out" a slave ship, Tom adamantly refuses. So, the Devil proposes that Tom become a usurer in his eagerness for more of those that he perceives as "special people." Since lending money at an exorbitant rate clearly appeals to Tom's greedy nature, he agrees. "I'll do it tomorrow, if you wish," he eagerly tells the Devil.
Tom is then instructed to open a broker's shop in Boston the following month where he will loan money and charge an interest on the loans of two per cent a month. The avaricious Tom responds, "Egad, I'll charge four!" They shake hands and depart.