On July 20, 1994, the United States issued two stamps to mark the 25th Anniversary of a human being’s first footsteps on the moon.  One was intended for use on Express Mail and bore a $9.95 denomination.  The other was a 29 cent commemorative stamp, covering the first class rate.   The stamps were the third and fourth in a sequence directly related to the First Manned Moon Landing and issued over a span of 25 years.  These four issues were linked by more than their theme:  Each was designed by an artist or artists with the surname of Calle.

The stamps were:

- A 10c airmail stamp (Scott C&^) issued September 9, 1969, to commemorate the successful lunar trip of Apollo 11 and it’s crew, Neil Armstrong, Buzz Aldrin and Mike Collins.  The designer was Paul Calle.

1. -A $2.40 priority Mail stamp (Scott 24190 issued July 20, 1989, in conjunction with the 20th Anniversary of Apollo X1.  The designer was Chris Calle, son of Paul Calle.
   

- With a fine sense of appropriateness, the United States Postal Service commissioned both Paul and Chris Calle to jointly design the 29c and $9.95 25th anniversary stamps of 1994.