The "Hot Air Balloon" postage stamps were issued in 1983. Celebrating the 200th anniversary of the first balloon flight, this set of four was released in both Albuquerque, New Mexico, and Washington, D.C. The balloons pictured are the "Intrepid," used by the Union Army during the Civil War, modern hot air balloons, and the "Explorer II," used by the National Geographic Society and the U.S. Army.
This listing is for 12 stamps total (i.e., 3 sets of the four stamps pictured herein).
Please note that if you use the stamps to mail a letter, please make sure that you use the correct amount as required by the United States Postal Service.