|Carte de Visite: young lady with bustle ca 1875|
A carte de visite was a small photographic portrait of a person, mounted on a piece of card. By the 1860s, entrepreneurs were mass-producing cartes de visite - small photographic prints that originated as calling cards - of well-known figures.
The 'ancestor' you may find among your cartes de visite may not be an ancestor at all but an important well-known figure of his time, such as a Prime Minister. Such cartes were collected and put into albums.