The process for these pictures was done by using a plate, made of copper and using silver iodide to expose the picture, along with exposure to light.Tin type pictures were introduced in 1853, and became extremely popular.
A number of books in our collection can aid in developing skills in this area. Subject headings to use to locate other titles in the catalog are: A good starting place, this volume covers types, care and restoration of photographs, the process of identifying and dating photographs, sources of useful information, a chapter on ways to locate photos other than the ones you already own, and a good bibliography of additonal sources. An extensively detailed analysis of photographs, including the social implications, of clothing styles for men, women and children of several ethnic groups.
They are all either in the adult circulating or the reference collections, generally under the class number 355.14 (or R 355.14, in the case of reference).
They can also be located in the catalog by using the subject headings: Many old photographs were printed on card stock that had postcard backs and could be mailed.
One of the things that can provide clues is the hair styles of the women in the picture, because just like today they changed hair styles.
While their hair would not be short, the type of bun, bangs or no bangs can provide hints to the age of the photograph.