A block of four 25-cent stamps commemorating four intrepid Antarctic explorers was issued on September 14, 1988, in Washington, DC. The dedication ceremony was in the Gilbert H. Grosvenor Auditorium at the National Geographic Society.
The four stamps, all designed by Dennis Lyall, honor Nathaniel B. Palmer (1799-1877), Charles Wilkes (1798-1877), Richard E. Byrd (1888-1957), and Lincoln Ellsworth (1880-1951). The designs have the same basic style Lyall used on the 1986 Polar Explorers stamps. Each depicts icy scenes of the explorers' means of travel, with a map of the polar region serving as a backdrop.
Palmer discovered Orleans Strait and the Antarctic Peninsula. Wilkes proved Antarctica to be a continent during his expedition from 1839 to 1843. Byrd conducted five expeditions to the region and supervised extensive scientific study as well as photographic mapping of the continent by air. Ellsworth was the first person to fly over both polar regions, and he led four expeditions southward during the 1930s.
The stamps were printed in the photogravure process by the American Bank Note Company and were issued in panes of fifty.
Postal Bulletin (August 11, 1988).