According to a USCIS Update:
“U.S. Citizenship and Immigration Services (USCIS) moved the agency Lockbox to a new location in Chicago on May 28. While the Post Office Box address is the same, the move changes the address for deliveries by private couriers (non-USPS).
The new address for deliveries by private courier is:
Attn: Please check Form Instructions for the proper Attn: information
131 South Dearborn, 3rd Floor
Chicago, IL 60603-5517
Express courier services have agreed to forward packages to the new site for 90 days (until Aug. 24, 2008). During this transition period, USCIS will accept and process without delay all cases otherwise properly filed.
Forms processed at the USCIS Chicago Lockbox include those associated with family-based adjustment of status, all Petitions for Alien Relative (Form I-130), and Temporary Protective Status.”