30 ILCS 570/1.1
The General Assembly finds and declares that unemployment in the Illinois construction industry has traditionally tended to be higher in those counties which border upon other states. Further, the General Assembly finds and declares that the over-utilization of out-of-state laborers on public works projects or improvements for the State of Illinois or any political subdivision, municipal corporation or other governmental units thereof is a contributing factor to higher levels of unemployment both in the border counties and throughout Illinois. It is the public policy of this State and the objective of this Act to promote the general welfare of the people of this State by ensuring that Illinois laborers are utilized to the greatest extent possible on public works projects or improvements for the State of Illinois or any political subdivision, municipal corporation or other governmental units thereof. To this end, this Act shall be liberally construed to effectuate its purpose.
30 ILCS 570/1.1