Express mail in the United States

The United States Postal Service (USPS) provides Priority Mail Express for domestic U.S. delivery as well as international delivery. The USPS formerly offered a second international express service separate from the EMS network, Global Express Guaranteed (GXG), which involved USPS offices acting as drop locations for international packages which would then be handled by the FedEx international delivery network.

Source: Wikipedia — Express mail in the United States (CC BY-SA 4.0)