5 ILCS 490/45

June 14, commonly known as Flag Day, is established as a day to be observed with fitting patriotic exercises in schools, colleges, universities, societies, clubs, and other organizations. On that day the Flag of the United States of America shall be appropriately displayed on all public buildings within the State of Illinois. It is also fitting that, as a symbol of the guarantee of the sanctity of the home, the flag be displayed from every home on that day and that, as a symbol of the guarantee of freedom of worship, public recognition be made in all places of worship on June 14th or on the Sunday preceding.