Besides appearing in the work of Hawthorne and Irving, does the Black Man of the Woods have any basis in other examples of literature or mythology?...

The Devil being referred to as "The Black Man" mostly likely has no one true origin in literature, but was a euphemism that had become widely accepted by the time period of Irving and Hawthorne. There are some aspects in the description of the Devil that play into a common idea of how evil should be embodied. The color black is almost always associated with nefarious intentions as well as corruption and just evil in general. For instance, the common idiom of saying someone has a "black heart" is unanimously taken to mean the person in question is evil and/or cruel. 

However, something else should be taken into consideration and that is the description of The Black Man in Irving's short story "The Devil and Tom Walker."

"It is true he was dressed in a rude Indian garb, and had a red belt or sash swathed round his body; but his face was neither black nor copper-color, but swarthy and dingy, and begrimed with soot, as if he had been accustomed to toil among fires and forges"

It directly states his face was black, not because it was the color of his skin, but because he was covered in soot. This plays back into the universally accepted notion that hell is a fiery pit of suffering. Due to the fire, it makes sense that an inhabitant of hell would be covered in the grime and soot produced by hell's fires. 

Thus, this euphemism for the Devil evolved naturally over time due to the already existing idea that the Devil lives among fire and the ensuing ash.