75 ILCS 65/2

The directors, trustees or managers of any public library which shall erect its library building in or upon any public park, under the terms and provisions as aforesaid, shall, so long as said building is maintained as a free public library, control, direct and manage the affairs of such library, as heretofore, under the terms and provisions of an act entitled, "An Act to encourage and promote the establishment of free public libraries in cities, villages and towns of this State," approved June 17, 1891, in force July 1, 1891, and in all respects the same as though the said building was not erected in or upon a public park.