Photographic technology developed rapidly between the heyday of tintype (1870s'ish) and when these pictures were made (1890s). See my other reply for some readi

Photographic technology developed rapidly between the heyday of tintype (1870s'ish) and when these pictures were made (1890s). See my other reply for some readings to learn more about late 19th century photography. (Also, photography was invented in the 19th century. I'm not sure why you make such sweeping claims about a whole century when exposures went from taking hours to fractions of a second over the course of it.)