Two portraits by John Durand are valued at a combined $400,000-600,000 ahead of Sotheby's Important American Folk Art.
The sale will take place in New York on January 25.
Little is known about Durand, a prolific and pre-eminent painter of wealthy families in the mid to late 18th century.
The paintings, which will sell in a single lot, are thought to have been produced for Captain Fitzhugh Green, an arctic explorer, and his wife.
Durand's work is easily identifiable through its bold colours and strong definition, with the subjects' fingers often splayed in a singularly idiosyncratic manner. Women are often depicted holding flowers.
A federal red and polychrome paint-decorated slant front desk is another highlight of the sale, valued at $300,000-500,000.
The desk originates from the Mahantongo Valley region in Pennsylvania and dates to around 1830, and features elaborate renderings of angels, birds and flowers.
The design is thought to have been based on illuminated texts brought to the area by German and Lutheran settlers - who were the earliest European inhabitants of the valley.
A fireboard with a view of Boston Harbor, attributed to the 19th century American school, carries an estimate of $250,000-250,000.
Designed to stand in front of a fireplace during the summer, the pine board is presented in its original frame and is thought to have been painted between 1825 and 1835.
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