He was a white guy.
"Whereas Hugh Gwyn hath . . . brought back from Maryland three servants formerly run away . . . the court doth . . . order [that] the first serve out their times with their master according to their indentures, . . . and that [the] third being a negro named John Punch shall serve his said master or his assigns for the time of his natural life here or elsewhere." A Virginia Court Decision (1640) from Virginia Magazine of History and Biography (January 1898), vol. 5, no. 3, p. 236.
John Casor who was brought over from Africa, was the first black slave. The owner was another black man Anthony Johnson.
Anthony Johnson was certainly among the first and likely the first in Massachusetts. Johnson himself was an indentured servant who had served out his contract.
Salem Poor was a former slave patriot who fought the British at Breeds hill. Poor was a slave who earned enough of his own money to buy his freedom from his master. I believe the price was around 40 shillings which was a considerable sum of money. Poor was recommended for commendation by 13 separate militia officers for his actions at Breeds hill.
The fact is that slavery is only as simple as the minds of those who try to simplify it.