An 1869 24c pictorial cover, sent to a whaling captain in Mauritius, sold for $14,500 at Robert A Siegel.
The lot headlined a sale of US and Confederate states postal history in New York on April 4.
It was sent from New Bedford and is the only known example of an 1869 24c pictorial on a cover addressed to the island.
The captain, Charles Henry Gifford, was a member of a prominent Massachusetts whaling dynasty.
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