5 ILCS 465/1
It shall be the duty of each county board to provide United States national flags of not less than four by eight feet in size, to be unfurled and kept floating from a suitable flag-staff to be placed on the top of the court house in its respective county, and it is hereby made the duty of the sheriff of each and every county in the state to see that the flag so provided shall be hoisted on its flag-staff above the court house and kept floating from eight o'clock A. M. to five o'clock P. M. on each and every legal holiday of the year, and on such other days as the county board may direct.
The county board may provide for the display of an MIA flag at the court house in its county, either upon the same flag-staff as the United States national flag or otherwise.
5 ILCS 465/1