Before the Civil War, practically all photographs made in the United States were either daguerreotypes or the imitations of them known as ambrotypes and tintypes. Superficially they all look alike, but in reality they are quite different. The daguerreotype was made with a silvered copper plate, the ambrotype with a glass plate, and the tintype on thin sheets of iron japanned black. A daguerreotype can instantly be recognized if the picture looks like an image on a mirror. Indeed, the process .....   Read Full Story