330 ILCS 115/4
The directors of the Chicago Public Library shall have the privilege of storing and keeping in such unoccupied portions of said Memorial Hall building as may not be required for other purposes, all such maps, charts, books, periodicals, papers and other literature relating to the late civil war and military history of this country, as they may desire. At the expiration of fifty years from the completion of said Memorial Hall building and at any time after the expiration of that period, the directors of the Soldiers' Home in Chicago, at their option, by a two-thirds vote of all their members, may turn over, transfer and convey to the directors of the Chicago Public Library all the right, title and interest of the Soldiers' Home in Chicago, in and to the said Memorial Hall building and grounds, and the said directors of the Chicago Public Library in such case are hereby authorized and empowered to receive, accept, hold and maintain the same in perpetuity; Provided, however, said building shall never be deprived of its distinctive character as a Soldiers' Memorial Hall, or be used by the directors of the Chicago Public Library or any other persons to the exclusion of the non-political organizations of the soldiers and sailors of the late civil war and such other organizations of United States soldiers, sailors and marines of succeeding wars and expeditions of the United States.
330 ILCS 115/4