Thirty years ago, one of the most comprehensive collections of U.S. stamps was taken off of display at the New York Public Library after several of the artifacts were stolen. Following the incident, the entire collection was locked away — until now.

Last week the National Postal Museum opened part two of the exhibit “Rarity Revealed: The Benjamin K. Miller Collection,” which includes a complete compilation of U.S. stamps issued from 1894 to 1925. Miller’s 19th-century U.S. stamps are the first complete collection ever assembled, according to Daniel Piazza, a research coordinator at the museum.

Piazza said the second installation begins with stamps from 1894 because that is the year when the Bureau of Engraving and Printing began to issue U.S. stamps, ending the printing of stamps by private companies. The public printing of stamps ushered in a “different era” for philatelists, he said.

The “inverted Jenny” stamp, which was one of the pieces that was stolen in the 1977 robbery but since has been recovered, is “the most iconic piece and the most important piece from Miller’s collection,” Piazza said.

The stamp, issued in 1918, contains an image of the Curtiss JN-4 airplane accidentally printed upside down. Miller bought it for $287.50, but it appreciated in value very quickly. Later in life, Miller attributed his interest in collecting stamps to this piece, Piazza said.

Also on display in part two of “Rarity Revealed” is a $1 stamp from 1898 called “Western Cattle in Storm.” That stamp is considered by some philatelists to be the most beautiful one ever issued, Piazza said.

The Miller collection also features a sheet of 2-cent, red George Washington stamps, which Piazza said were produced in bulk. What makes this particular sheet of 16 stamps unusual is the fact that it is missing a perforated edge. The sheet also was torn during production at the Bureau of Engraving and Printing but was patched up before being sent out for distribution, making it all the more distinctive, Piazza said.

Miller, an attorney from Milwaukee, donated his extensive stamp collection to the New York Public Library in 1925, three years before his death.

The collection remained there on display until the 1977 robbery. More than half of the stolen objects were recovered during the 1980s, but many pieces still have never been found, according to the Smithsonian Institution Web site.

“You’ve got to have deep pockets,” to build a collection like Miller’s, Piazza said. “But even deep pockets can’t do it [completely],” he said, noting the rarity of pieces like the 1-cent Z-grill, which appeared in part one of the National Postal Museum’s exhibit.

The Z-grill was only used for a brief period and only two copies are known to exist, making them the rarest U.S. stamps, according to the Smithsonian’s Web site. Miller’s 1-cent Z-grill was the first one ever identified and it was not until after his lifetime that the 15-cent Z-grill was discovered.

The collection contains 25,000 stamps and is still owned by the New York Public Library. It is currently being loaned to the National Postal Museum until 2009.

The first part of the exhibit, which contained stamps issued between 1847 and 1894, was on display from May 27, 2006, until Oct. 1 of this year.

“Rarity Revealed” was divided into two parts in order to show as many pieces as possible, rather than to reduce the collection, according to a press release issued by the Postal Museum.

Part two of the exhibit opened to the public on Nov. 5 and will remain on display until Jan. 12, 2009.

The National Postal Museum is open to the public daily (except Dec. 25) from 10 a.m. to 5:30 p.m. Admission is free.