“USPS lookup tracking number” is a __noun__ that refers to a unique identifier assigned to a package or mail item by the United States Postal Service (USPS). This number allows you to track the status of your shipment and estimate its delivery date, similar to how you would use a tracking number from any other shipping carrier.
USPS lookup tracking numbers are crucial for e-commerce businesses and individuals alike, as they provide visibility into the shipping process and peace of mind to customers. Historically, tracking numbers have been an integral part of the USPS since the introduction of automated sorting and tracking systems, revolutionizing package delivery.