A block of four imperforate US 1856 5c Jefferson red brown stamps will auction for an estimated $45,000 at Robert A Siegel.

It's among the finest of the five used blocks extant.

This imperforate 1856 5c block is one of five used specimens

It's unclear why the US Post Office issued the 5c issue after 1851, as the postage rates changed - making this denomination obsolete.

Yet it continued printing both the 5c and 10c Jefferson issues.

Scholars suggest the series was continued to pay the international open mail rates, which came to 5c with the addition of a small surcharge.

The lot is one of a number of pieces from the Eubank collection, which will be sold on December 13 to raise funds for the William H Gross Stamp Gallery at the Smithsonian Institute in Washington, DC.

The auction house comments: "Gordon and Ronda Eubanks have generously agreed to donate the proceeds from the sale of select items from Mr. Eubanks' award-winning collection of 1851-56 Issue stamps and covers, which make up almost all of the lots in this sale…

"This sale should create momentum for the campaign to create a substantial multi-million dollar endowment fund. We urge bidders to bid even more enthusiastically, with the knowledge that the proceeds will benefit philately's most important museum."

We have a expertly curated selection of rare stamps for sale.  

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