An elaborated article about USPS package tracking:
The United States Postal Service (USPS) is the national postal service of the United States. The USPS is an independent federal agency and operates with the mission to provide reliable, efficient, and affordable mail service to everyone in the United States, regardless of location.
When a package is mailed, the USPS assigns a tracking number to it. This number can be found on the shipping label, or on the package itself if it was sent through the mail.
The USPS also releases a tracking update once the package has been scanned at the delivery station.
If you have not received your package within the expected time frame, you can contact the USPS to inquire about the status of your package. You can also try to contact the shipping company to inquire about the delivery.
If you have not received your package, you may want to consider filing a claim with the USPS.