This non-denominated stamp was placed in use at the time that the first class postage rate went up to 18 cents. This is the second in a series of such stamps, which were intended for use until stamps printed with the new denomination were available for mass distribution.

The bald eagle, Haliaeetus leucocephalus, is the national emblem of the United States. It is protected by law, but even then some large eagles are killed by farmers and gamekeepers or captured for use in falconry. As with other birds, the bald eagle has been affected by the widespread use of pesticides that, when ingested, can weaken eggs. Eagles are predatory birds that historically have been the symbol of courage, immortality, and power since ancient times.

All eagles have large and heavy hooked bills and strong, sharp claws called talons. The bald eagle is not really bald, but is so named because of its white head. Eagles prey on small creatures: birds, fish, rabbits, other rodents, and snakes. They have very keen eyesight and hunt while soaring high in the air or watching from a high perch. An eagle's nest normally is high in a tree or on a rocky ledge where it cannot be reached easily by other animals or humans. This precaution is important because young eagles remain helpless for a long period.