The Class of 1945 Library was the site of the second-day issue of a set of stamps titled “Masterworks of Modern American Architecture” that included the Library. Complete with officials from the U.S. Postal Service, the stamps were unveiled at a ceremony in the Library's Michael Rockefeller '56 Hall on May 20, 2005.

Designed by Louis I. Kahn, the library was one of 12 buildings featured on the panel of first class commemorative postage stamps. Other buildings honored in the series included the Guggenheim Museum in New York City, designed by Frank Lloyd Wright; the Walt Disney Concert Hall in Los Angeles, designed by Frank Gehry; the Yale Art and Architecture Building in New Haven, CT, designed by Paul Rudolph; and the East Building of the National Gallery of Art in Washington, D.C., designed by I.M. Pei.  All of the buildings were built between 1930 and 2003.

The unveiling of the stamp and the second day issue ceremony were attended by state and local officials, as well as U.S. postal service officials. Everyone who attended the event received a special commemorative second day cover.  A cover is a philatelic term for an envelope, with the commemorative stamp attached, which has a special cancellation and also bears a cachet, or decorative illustration in the lower left corner of the envelope. Sheets of the stamp were also available for purchase.

A replica of the stamp is on display in the library.