The United States Postal Service (USPS) is an independent agency of the United States government, established in 1971 as an "independent establishment of the executive branch", responsible for providing postal service in the United States. It is one of the few government agencies explicitly authorized by the United States Constitution. Within the United States, it was formerly referred to as the "Post Office" or "U.S. Mail". It is currently referred to as the "Postal Service", and officially as the "U.S. Postal Service".
The USPS's first incarnation was established by Benjamin Franklin in Philadelphia in 1775, by decree of the Second Continental Congress. The Post Office Department was created from Franklin's operation in 1792, as part of the United States Cabinet, then was transformed into its current form in 1971, under the Postal Reorganization Act.
Since its reorganization into an independent organization, the USPS has become self-sufficient and has not directly received taxpayer-dollars since the early 1980s with the minor exception of subsidies for costs associated with the disabled and overseas voters. However, it is currently borrowing money from the U.S. Treasury to pay its deficits. The decline of mail volume, due to the increased usage of email, has forced the postal service to look to other sources of revenue while cutting costs to maintain this financial balance.
Employing 596,000 workers and over 218,000 vehicles, it is the second-largest civilian employer in the United States (after Wal-Mart) and the operator of the largest civilian vehicle fleet in the world. The USPS is obligated to serve all Americans, regardless of geography, at uniform price and quality. It has exclusive access to letter boxes marked "U.S. Mail." It competes against private package delivery services that are not supposed to deliver to letter boxes but may leave packages by front doors if no one is available to receive them.