65 ILCS 5/11-68-1

For the purpose of promoting the health and welfare of its citizens, any city with a population of more than 30,000 whose corporate limits coincide with the limits of the township in which the city is located, subject to a referendum vote, may acquire and improve not to exceed 10 acres of land, within or without the city, to be set apart, held, and maintained as a stadium and athletic field for the use of the public.