United States Government--post Offices, Winslow Freeport, IL 61032 Phone : (815) 367-3601 Business Category Post Offices Government Offices & Public Schools Post Office - Winslow 200 Carver St Winslow, IL 61089 Phone : (815) 367-3601 Business Category Post Offices Toll-Free           (800) ASK-USPS Fax           (815) 367-2901