The first reference to Amy is in the February 15, 1968 comic strip in which Snoopy lists her as one of the many girls who sent him valentines. The character is referred to again in the same context in the strip from February 16, 1971. In the September 5, 1971 strip, Lucy van Pelt boasts that she knows all the people in the world and names Amy among them. In the Sunday strip from December 17, 1972, Snoopy sends her a Christmas card.
Apparently, Amy's birthday is August 5 as the greeting "Happy Birthday Amy" appears in many August 5 strips. Sometimes this message is written on Snoopy's doghouse. This message first appeared in 1973. Other years this occurred were 1974, 1979, 1984, 1986, 1991, 1995, 1996, 1997, and 1998.
Behind the scenes
Amy is one of Charles M. Schulz's daughters. The other two are Jill and Meredith (the other two children being sons Monte and Craig). She is married to John Johnson and now lives in Alpine, Utah, with a large and happy family, where she rides horses and runs an LDS bookstore.
On August 5 Schulz often penned the words "Happy Birthday Amy" somewhere into the strip, usually along one of the margins.
Amy has several original strips, including those that mention her, tucked away safely in a vault.