Introduced in the 1850s as an affordable alternative to the daguerreotype, an ambrotype is essentially a glass-plate negative that appears as a positive image when laid against a black backing. This small example, with three generations of a family packed into its frame, would have been made at a relatively small cost, but nonetheless treasured by those depicted. Unlike paper prints, which were more easily signed, inscribed, or stamped, daguerreotypes, ambrotypes, and tintypes have often lost their history of authorship and ownership as they have passed from family attics to flea markets to the art market.