Portrait miniatures were not meant to be seen by the world at large but were intended as intimate images to be privately viewed. Usually painted in watercolor on ivory, early miniatures were worn in lockets–where they were close to the heart–tucked into a waistband, or held in the palm of one's hand, capturing the presence of one who had died or was far from home. Later portraits often were housed in leather cases so they could be carried or placed on tabletops. The earliest portrait miniatures can be traced to sixteenth-century England, where the art was called limning, meaning "to illuminate." Portraits in miniature followed trends found in full-scale portraiture and frequently were painted by the same artists. Most are unsigned, however, and it is often difficult to attribute a miniature to an artist better known for his full-scale portraits.

This miniature is attributed to Isaac Sheffield, a portrait painter in New York City and New London, Connecticut, who was the son of Isaac Sheffield, a sea captain who advertised in New London, New York City, and Sag Harbor, New York, directories, often as a "ship-master." In 1828 the younger Sheffield was listed as a miniature painter in Lower Manhattan; the following year he was residing in Brooklyn. By 1830 he was listed as both a miniature and portrait painter, but he moved to New London after his father's death later that year. Here he appears to have made a career painting the many sea captains who sailed from the port, as well as their families. Sheffield's signed miniatures only rarely have included the whaling ships and scenes that he regularly included in his large portraits. This miniature is intricately detailed, with the costume delineated in precise, black-on-black strokes and featuring drapery cords, jewelry, watch chains, and watches in gold metallic paint.

Stacy C. Hollander, "Miniature of a Sea Captain," in American Anthem: Masterworks from the American Folk Art Museum (New York: Harry N. Abrams in association with American Folk Art Museum, 2001), 323.