Keywords: Wildlife antelope 1956 U.S. stamp.1.jpg en Wildlife conservation was highlighted with a series of three commemorative stamps in 1956 The 3-cent Pronghorned Antelope stamp was issued June 22 1956 designed by Robert W Bob Hines a government artist at the Department of the Interior 1956-06-22 U S Postal Service; http //arago si edu/category_2029398 html National Postal Museum Bureau of Printing and Engraving PD-USGov Stamps of the United States 1951-1960 Commemorative stamps of the United States Works by Robert W Hines Ruminantia on stamps 1956 stamps of the United States Brown stamps |