Born in Bath, Maine in 1806, William Matthew Prior spent the formative years of his career principally as a sign and ornamental painter in Portland, Maine. He painted his first portrait in Portland in 1824, where he also collaborated with his in-laws, the Hamblens. By 1841, Prior had moved to Boston where he and several members of the Hamblen family established "The Painting Garret," producing landscapes and portraits of local patrons at varying prices according to size, medium and style. Prior also painted as as itinerant, executing likenesses of sitters in communities as nearby as New Bedford and Newport, and as far south as Baltimore.