A block of four 25-cent Classic Mail Transportation commemorative stamps went on sale November 19, 1989, in Washington, DC. The stamps were issued during WORLD STAMP EXPO '89, the first international philatelic exhibition ever directly sponsored by the US Postal Service. The show took place November 17-20 and November 24-December 3. It was held in conjunction with the twentieth Congress of the Universal Postal Union.
The stamps feature vehicles that have delivered mail and range from colonial America to the early twentieth century. The colorful quartet displays four of the most commonly used means of transporting mail across the American landscape since the mid-eighteenth century: the stagecoach of 1850s, paddlewheel steamer, biplane, and depot-hack type automobile.
The stamps were designed by Mark Hess and produced by the offset/intaglio process in panes of forty.
Postal Bulletin (October 19, 1989).