us mail ground shipping is a service provided by the United States Postal Service for transporting packages and mail overland within the U.S. USPS Ground Shipping is one of the most cost-effective shipping methods for heavier or larger packages. This service offers delivery within 2-8 business days, depending on the distance between the origin and destination. It’s a reliable and affordable option for businesses and individuals who need to send packages that are not time-sensitive. USPS Ground Shipping is also an excellent option for heavier items, as the pricing is based on the weight and size of the package.