105 ILCS 5/10-21.3

To establish one or more attendance units within the district. As soon as practicable, and from time to time thereafter, the board shall change or revise existing units or create new units in a manner which will take into consideration the prevention of segregation and the elimination of separation of children in public schools because of color, race or nationality. All records pertaining to the creation, alteration or revision of attendance units shall be open to the public.