Reverse painting on glass, 22" x 18" and 28" x 22" in what appears to be the original frame (not shown). bio from askart.com: Born in Bath, Maine, William Prior became an itinerant portrait and landscape painter who also painted on glass. In 1841, he settled in Boston after traveling and painting widely for ten years around New England. In 1824, he had been in Portland, Maine and lived there from 1831 to 1840. He advertised in the "Maine Inquirer" in 1831 that "persons who wished a flat picture can have a likeness whithout shade or shadow at one-quarter price" (Falk).
It was this style of primitive painting for which he became best known, but he also painted on glass with more sophistication, including copies of Gilbert Stuart's "Athenaeum" portrait of George Washington and portraits of Washington and his wife Martha. In his later years, he was assisted by his two sons, Gilbert and Matthew Prior. He called his studio The Painting Garret, and some of his works from the studio were signed "Painted in Prior's Garret". He was also the author of several religious books.
In Boston, he established a portrait studio with his brother-in-law, Sturtevant Hamblin, and he stayed there until 1846, when he moved to East Boston. He also traveled to New Bedford, Massachusetts. Prior was unique in that his style varied with the price paid by the sitter. He advertised that less expensive portraits would be a "flat picture" and that those persons paying more would have more realistic depictions.
He is best known for his primitive "flat" work, especially full-length child portraits with vibrant colors and little detail on hands and feet. He differed from many contemporary portrait painters in that he placed his subjects against a soft, atmospheric background rather than one of bright color.