The Pan-American issue is the first of the twentieth century. The six-value set was released for the Pan-American Exposition, held in Buffalo from May 1 to November 1, 1901. In common with the Trans-Mississippi series, the Pan-Americans were issued during the McKinley administration.

The protests of collectors against high face-value stamps in response to the Trans-Mississippi issue was apparently heard. The Pan-American set could be purchased for 30 cents versus $3.80 or $16.34 for the previous commemorative sets.

The Pan-American stamps depict images capturing new concepts and ideas for a new century—an automobile, train, fast steamship, and man-made canal. To express this high-tech era with enthusiasm, each stamp was printed in two colors. The set was the Bureau of Engraving and Printing’s first attempt at bicolored postage stamps and the Post Office’s first bicolored general release since the 1869 Pictorials. In common with their 1869 counterparts, the Pan-American Issue created three inverts.

The 1c and 2c Inverts were issued through post offices. The errors occurred during the two-stage printing process—center first, frame second—resulting from the pressman’s mistake in turning the sheet 180 degrees from the correct orientation after the first impression. Technically speaking, the Pan-American inverts have inverted frames and not inverted centers.

Sheets of the 1c are known to have been sold at at least four different post offices. According to Johl the first copies were found by a jewelry firm in Bessimer, Alabama, who intended to use them on letters. Between 600 and 700 are likely to have been issued. Despite the relatively large number that was issued, unused blocks are surprisingly rare. Our Levi records show thirteen blocks of four, a block of six, and a block of 20 existing at one time, but some portion of the smaller blocks were certainly divided into singles. We also show two strips of four and three pairs. There are three covers recorded, including one offered in our 1999 Rarities of the World sale.

The 2c Pan-American Invert is a much rarer stamp. It is likely that only 200 stamps were sold by the post office, and these quickly reached the hands of appreciative collectors. It is surprising, then, that only two blocks of four are known (one reconstructed). Only seven examples are recorded used .

The 4c Pan-American Invert was not regularly issued by post offices and is actually a special printing released to collectors through official channels. If the reported numbers are correct, a total of 203 4c Inverts was released. One sheet of 400 stamps was printed. An unknown quantity was overprinted with a small "Specimen" handstamp. Some of these, both with and without overprint, were given away by Third Asst. Postmaster General Edwin C. Madden. When postal authorities learned of the practice, they destroyed 194 of the remaining copies and put one pane of 100 into the official archives, which was stuck down on a page. At a later date, 97 of the 100 stamps in the official archives were traded with stamp dealers for rarities missing from the official archives. This accounts for the disturbed state of gum on virtually all of the 4c Pan-American Inverts without overprint. There are seven blocks of four contained in our records.

It was rumored that sheets of the 5c, 8c and 10c were also prepared as inverts, but that these were destroyed after officials learned of the unofficial release of the 4c stamps. No examples are known.