You can contact the Postmaster General's main office by calling the main United States Postal Service customer contact number, 1-800-ASK-USPS. The mailing address of the Postmaster General is 475 L'Enfant Plaza, Washington DC 20260.
The Postmaster General's main office is open Monday through Friday from 8 a.m. until 8:30 p.m. and on Saturday from 8 a.m. until 6 p.m. Eastern Time. The first person to be appointed to the position of Postmaster General by the Continental Congress was Benjamin Franklin. He held the position for approximately 15 months. From 1829 until 1971, the Postmaster General was a member of the President's Cabinet.