The painting by Kara Walker, a renowned African-American artist, was hung in the library the week of Thanksgiving, The (Newark, N.J.) Star Ledger reported.
It depicts the horrors of reconstruction, 20th century Jim Crow conditions and the hooded figures of the Ku Klux Klan, as well as a white man holding the head of a naked black woman to his groin.
"I didn't notice it at first," said Kendell Willis, a library services employee. "Then I looked up and was blown away."
Willis and other library employees sent emails to Library Director Wilma Grey, requesting the work be taken down.
"It can go back where it came from," said Sandra West, a library associate. "I really don't like to see my people like this. We need to see something uplifting and not demeaning."
Grey said she didn't think there would be this kind of reaction.
"It evokes man's inherent ability to be unkind to people," Grey said. "It's meant to evoke some kind of emotion that says all of these terrible things happened and that we should not be complacent."
Grey said she plans to hold a staff meeting to discuss the artwork.
"When it comes to art, you are allowed to react one way or the other," Grey said. "It's entirely personal."