The USPS traces its roots to 1775 during the Second Continental Congress, where Benjamin Franklin was appointed the first postmaster general. The cabinet-level Post Office Department was created in 1792 from Franklin's operation and transformed into its current form in 1971 under the Postal Reorganization Act.
- Sometime before 1883 advertising for various products was printed on the back of U.S. three-cent stamps.
- The world's largest post office is the head post office in Chicago, Illinois. The smallest post office in the world is located in Ochopee, Florida.
- When stamps were first issued, they had no gum on the back.
- If paste was not available, mailers sometimes pinned or even sewed stamps to envelopes.
- In 2008, stamp and retail sales at the Postal Store totaled more than $442 million.
- Recycles more than one million tons of materials annually.
- Handles more than 41 million change-of-address cards each year as a free service to the 17% of the nation's population that moves each year.
- Delivers more in one day than FedEx does in a year, and more in three days than UPS does in a year.
- Operates a $5.5 billion transportation network that includes more than 200,000 vehicles and contract space on approximately 15,000 commercial flights daily.
- The postal service is listed by Fortune Magazine as 29th on a list of the world's largest companies. Working with an annual budget of nearly 1% of the United States economy.