Ling Ling and Hsing Hsing

(Wikipedia) - Ling-Ling (1969 - December 30th, 1992) and Hsing-Hsing (1970 - 99) were two Giant Pandas given to the United States as gifts by the government of China following President Richard Nixon's visit in 1972. In return, the U.S. government sent China a pair of musk oxen.
They arrived at the National Zoo in Washington, D.C., on April 16, 1972, at a ceremony attended by First Lady Pat Nixon. While at the zoo, they attracted millions of visitors each year. Continued

Photo: Ling-Ling and Hsing-Hsing, Smithsonian.