One center is in Aurora, and 520 people work there. The other facility is near O'Hare Airport, and it employs 600 people. In all, 250 processing centers around the country are being considered for closure.
Others in Illinois are facilities in Bloomington, Carbondale, Centralia, Effingham, Quincy, Rockford and Springfield.
The postal service also wants to end overnight delivery of letters and postcards.