55 ILCS 5/5-38002
In performing this duty, the county board may, if it is deemed advisable, contract in writing, with an existing library or libraries in any county, to establish, equip and maintain a public county library service. The contract shall contain provisions requiring the contracting library or libraries to (a) establish, equip and maintain a county library; (b) establish, equip and maintain such branches and stations of the county library in the various parts of the county as may be deemed necessary by the county board; (c) acquire and circulate books, periodicals, pamphlets, musical scores and records, pictures, stereopticon slides, motion picture films and other educational material, (d) do all other things necessary to carry on an efficient public county library service; also such contract shall contain provisions specifying that one or more representatives of each party to the contract, may participate in and vote at all meetings in which matters relating to the library service, furnished under the contract, are considered.
The making and performance of any such contract shall be under the supervision of the county board.
55 ILCS 5/5-38002