United States airmail service
United States airmail was a service class of the United States Post Office Department (USPOD) and its successor United States Postal Service (USPS) delivering air mail by aircraft flown within the United States and its possessions and territories. Letters and parcels intended for air mail service were marked as "Via Air Mail", appropriately franked, and assigned to any then existing class or sub-class of the Air Mail service.
Cover flown on the first day of scheduled Air Mail Service in the U.S. and franked with the first U.S. Air Mail stamp, the 24 Cent "Jenny"(C-3). Cancel: "AIR MAIL SERVICE – WASH. N.Y. PHILA." "MAY 15, 1918 – FIRST TRIP" "PHILA." (Type: USPOD CDS w/killer bars)
Wise ascends on the first United States balloon airmail from Lafayette, Indiana in 1859.
Eddie Hubbard (left) and William E. Boeing stand in front of a Boeing C-700 seaplane near Seattle.
The first U.S. Air Mail takes off from Washington, D.C., on May 15, 1918.
United States Post Office Department
The United States Post Office Department was the predecessor of the United States Postal Service, established in 1792. From 1872 to 1971, it was officially in the form of a Cabinet department. It was headed by the postmaster general.
First U.S. postage stamps, authorized by Congress March 3, 1847. Earliest known use of the 5¢ Franklin is July 7, 1847, and the 10¢ Washington is July 2, 1847.
Mineral Wells, Texas, post office, built between 1911 and 1913
Mail truck loaded with gold leaving the New York City Assay Office in 1941