N.J. Stat. § 34:9-1
It shall be unlawful for the state or any county, municipality, board, committee, commission or officer thereof, officer, body or organization having charge of any public work or any construction, whether the same be a building, excavation, pipe-laying, bridge or dock-building, sewer or drainage construction, road building, paving, or any other form or kind of public work, which shall be undertaken and done at public expense or for any person or corporation, to employ as a mechanic or laborer upon such public work or construction, or any part thereof, any person who is not at the time of such employment a citizen of the United States. Any contractor or officer who shall violate the provisions of this section shall forfeit and pay the sum of one hundred dollars, with costs, to be recovered in an action at law in any court of competent jurisdiction, which penalty when recovered shall be paid into the treasury of the state, or county or municipality within which and under whose authority such officer or contractor claims to act.
N.J.S. § 34:9-1