The institutions listed below have specialized collections of military images which are generally well indexed. An extensive search might uncover images of interest, but such a search would need to conducted in-person by the researcher or his/her representative.If there is a building, maybe the family home, in the background then the facade can give you clues to the date of the photograph.If there are buildings in the picture that do not exist today then this also can pinpoint the age of the photo.You may be surprised to learn that an old photograph can bring you closer to your ancestors.
And quite possibly you want to know more about them.
Furniture is a great way to tell the age of the photograph.
It is obviously similar to the fashion and hairstyle clues I have already pointed out.
Another aspect of a photograph that may draw your attention is the background.
The details that are behind our ancestors can also give us a clue as to the date of the photograph.