It will vary on the mail type. Mail from Chicago, IL to New York City, NY can take 1-3 business days.
USPS offers:
Priority Mail Express 1-Day
Priority Mail 2-Day
First-Class Mail® Stamped Letter (3 days)
You may calculate expected delivery date and domestic shipping costs using the Postage Price Calculator at Usps.com.
For inquiries you may call USPS Customer Care Center on 1-800-ASK-USPS® (1-800-275-8777). Lines are available Monday to Friday from 8am to 8:30pm ET and Saturday from 8am to 6pm ET.
Make smart choices. Here's how mailing services can be combined to meet your needs shared by USPS.