https://www.uscis.gov/i-485-addresses
If you are filing because:
Spouse, parent, unmarried son/daughter under age 21 of a U.S. citizen with either an approved Form I-130 or you are filing Form I-485 together with Form I-130,Then file your Form I-485 at:
USCIS Chicago Lockbox
For U.S. Postal Service (USPS) deliveries:
USCIS
PO Box 805887
Chicago, IL 60680-4120
For Express mail and courier deliveries:
USCIS
Attn: FBAS
131 South Dearborn - 3rd Floor
Chicago, IL 60603-5517
When applicable, you must include a copy of the Form I-797 Notice, showing that your Form I-130 or Form I-360 was accepted or approved.