The U.S. Postal Service issued The Pan-American Inverts souvenir sheet on March 29, 2001. This souvenir sheet includes reproductions of the famous Pan-American inverts in their original colors as well as four reproductions of a "cinderella" that originally commemorated the 1901 Pan-American Exposition. (A cinderella is an item that resembles, but is not, an official government-issued postage stamp.) The design of the red and blue, diamond-shaped cinderella features a charging buffalo in the center encircled by the words "Pan- American Exposition Buffalo." The addition of an 80-cent denomination makes each of the four cinderella reproductions official postage stamps. A detail of the cover illustration from a 1901 souvenir guide also appears on the 2001 souvenir sheet. In the illustration, an allegorical female representing unity among the Americas stands on top of a globe. In her left hand she holds a flag - half Canadian, half American - and her right arm rests on the back of a buffalo. The globe shows the western hemisphere and includes the words "Pan-American Exposition 1901. Buffalo, NY, USA." Niagara Falls appears in the background.