An 1855 Kellogg & Co $50 piece will lead a sale of US coins at Heritage Auctions in Chicago on April 23-27 with a $180,000 starting bid.
The PR64 graded lot is the finest known example of the issue, which was minted in San Francisco in the mid 1800s.
Kellogg & Co opened for business in the city in 1853 against a chaotic backdrop.
The San Francisco Mint was not yet open and the majority of the private issue coins were melted down - leading to a surplus of gold and a lack of coins to convert it.
The $50 piece was issued in 1855 although it was not entered into circulation as the Mint became fully operational, negating the need for private assayers.
Only around 14 examples are known to exist - meaning that the coin was likely produced as a proof.
While no estimate is available, the coin achieved $300,000 at its last sale in 1980. Additionally, an example of the same grade sold for $747,500 at Heritage Auctions in 2007.
An 1893-S Morgan dollar will auction with an opening bid of $160,000.
The issue was minted in a limited run of 100,000 as the government was forced to mandate a reduction in silver coinage due to a run on gold resulting from the financial panic.
The example offered in the sale sold for $299,000 at Heritage Auctions in 2009.
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