55 ILCS 5/6-4001

Any county with a population of more than 300,000 and an increase in population of 30% or more from any decennial census to the next such census, by resolution of its county board may incur indebtedness for the reconstruction and remodeling of an existing courthouse or the construction of a new courthouse and related facilities at the same or a new location and for the acquisition of land and fixtures therefor, issue and sell general obligation bonds therefor and levy taxes upon all taxable property of the county sufficient to pay the principal on the bonds at maturity and to pay interest thereon as it falls due.