5 ILCS 525/1
Jurisdiction over the following described lands in the County of Champaign, State of Illinois, is hereby ceded to the United States of America:
First. Over the East three-quarters (E 3/4) of the North Half (N 1/2) of the South half (S 1/2) of the Southeast Quarter (SE 1/4) of Section Twelve (12), Township Twenty-one (21) North, Range Nine (9), East of the Third (3rd) Principal Meridian, containing thirty (30) acres, more or less; and
Second. Over the North half (N 1/2) of the Southeast Quarter (SE 1/4) of Section Twelve (12) Township Twenty-one (21) North, Range Nine (9) East of the Third (3rd) Principal Meridian, containing Eighty (80) acres more or less.
However, there is reserved to this State concurrent jurisdiction for the execution, upon all said lands, or in or on the structures erected thereon, of all process, civil or criminal, lawfully issued by the courts of this State. There is further reserved to this State the right to make arrests upon all said lands, or in or on the structures erected thereon, of persons violating State laws, and also the right to tax according to the laws of this State.
5 ILCS 525/1