There is virtually no information on Bartelby's past. He is an engima, and constucted so purposely by Melville. Bartelby is the image of those he reflects, like a sort of horrific mirror. He works diligently, yet there "was no pause for digestion." Bartelby works "silently, palely, mechanically."
There is something strangely appealing about Bartleby's standard response to the button-down world in which he lives, which is "I would prefer not to." So too would most office slaves, but Bartelby, without explanation or history, offers on this phrase to free himself from senseless obligation.
When Bartlebly is taken away, he offers no more resistance to this imprisonment than his former office captivity. When the narrator discovers him, Bartleby is "stooped over, and nothing stirred...his dim eyes were open; otherwise he seemed profoundly sleeping." How different is this, really, than those who stoop over desks eight or more hours a day and lead empty lives? We need not have much "background" information on Bartleby because his story, without the passive resistance, is so often told, and unfortunately, lived.